Colonies usually flabellate, with blunt branch tips. Coenosteum reticulate-granular and of many colors. Gastropores aligned along branch edge or, more rarely, meandering in lines on colony faces, the gastropore rows flanked (usually on both sides) by rows of horseshoe-shaped dactylopore spines. Gastro- and dactylopore tubes axial, extending along branch axis. Dactylostyles absent. Gastrostyles elongate (needle-shaped), often stabilized by transverse tabulae; a diffuse ring palisade sometimes present. Ampullae usually superficial and clustered.

Equally diverse in tropical and temperate waters as well as in shallow and deep environments, Distichopora is known from 26 Recent species and two fossil species (see Appeltans et al. 2001: WoRMS data base: www.marinespecies.org). The genus was revised by Boschma (1959) and Cairns (1983b).

Millepora violacea Pallas, 1766, by monotypy.

Eocene to Recent: cosmopolitan except for off Antarctica, 1-806 m.

Holotype, Alb-3480, a female colony (dry) of 9 cm length (USNM 43274, Fig. 1B). Paratypes, Alb-3480, include 3 male, 4 female, 1 indeterminate dry colonies, and SEM stubs 1489–1494 (USNM 76810) and 2 dry female colonies from Alb-4781 (USNM 76375).

Alb-3480: 52°06'00"N, 171°45'00"W (Amukta Pass, Aleutian Islands), 518 m.

Alaskan Leader 40, 52°09'18"N, 175°40'42"W, 174 m, 8 Jun 2002, 1 female and 1 male, USNM 1122542; Alaskan Leader 54–14, 51°44.4'N, 178°16.7'W, 567–680 m, 11 Jun 2002, 6 indet., AB02–29; Alaska Trojan, 51°24'47"N, 178°50'02"W, 640 m, 2 Feb 2000, 1 female, USNM1122447; Ballyhoo, 54°49'52"N, 178°43'14"E, 236, 7 June 2000, 1 female, USNM 1122565; Delta 5600, 52°33'47"N, 179°26'45"W, 225 m, 15 Jul 2002, 1 male, USNM 1122543; Dominator 971–181, 51°27'43"N, 178°35'20"E, 384 m, 27 Jul 1997, 1 female and 1 male, USNM 1123357; Dominator 971–219, 53°00'03"N, 172°18.86'E, 223 m, 4 Aug 1997, 1 female, 2 male, USNM 1123358; Jason2–2103–7-4, 51°47.898'N, 179°57.169'E, 1267 m, 1 female, AB08–0036; MF 70, 52°03'24"N, 179°25'06"E, 174 m, 1 male, USNM 77047; Ocean Olympic, 52°04.78'N, 177°13.39'E, 256 m, 1 male, AB00–57; Ocean Olympic, 52°08.67'N, 176°35.46'E, 292 m, 1 female, AB00–21; Ommaney 8, 56°11'42"N, 135°06'31"W, 53 m, 17 Aug 2006, 1 female in alcohol, USNM 1086324; Patricia Lee, 51°53.44'N, 179°47.7'E, 298 m, 1 indet., AB00–41; Sea Storm 36, 53°05'45"N, 171°41'56"E, 458 m, 19 Jun 2002, 1 female and 1 male in alcohol, USNM 1076507 and 1122770; Sea Strom 92, 51°33'34"N, 177°36'59"W, 367 m, 4 Jul 2002, 7 males, USNM 1137601, 1123541, 1122874–76; Sea Storm 93, 51°50'59"N, 178°26'02"E, 390 m, 5 Jul 2002, 2 male, USNM 1122877 and 1123287; Sea Storm 105, 52°08'59"N, 176°02'17"E, 201 m, 8 Jul 2002, 2 female in alcohol, USNM 1122884; Sea Storm 106, 52°10'46"N, 175°10'34"E, 165 m, 8 Jul 2002, 1 female and 1 male in alcohol, USNM 1122885 and 1123288; Sea Storm 107, 52°10'28"N, 175°14'14"E, 214 m, 8 Jul 2002, 4 female and 2 males in alcohol, USNM 1122866–70; Sea Storm 108, 52°11'32"N, 175°17'E, 208 m, 8 Jul 2002, 1 female and 3 males, USNM 1122862–65; Sea Storm 109, 52°17'16"N, 175°20'56"E, 238 m, 8 Jul 2002, 6 female, 8 male, 3 indet. in alcohol, USNM 1122886 and 1123289; Sea Storm 122, 52°02'49"N, 175°16'54"E, 143 m, 13 Jul 2002, 2 female and 7 males, USNM 1122858–61; Sea Storm 132, 52°12'02"N, 176°05'56"E, 150 m, 15 Jul 2002, 1 female in alcohol, USNM 1122854; Sea Storm 133, 52°13'40"N, 176°02'13"E, 148 m, 15 Jul 2002, 1 male, 2 females in alcohol, USNM 1122855–57; Sea Storm 149, 52°30'15"N, 173°33'03"W, 239 m, 21 Jul 2002, 1 male in alcohol, USNM 1122883; Sea Storm 151, 52°33'40"N, 173°33'03"W, 203 m, 21 Jul 2002, 1 female and 2 male, USNM 1122878–80; Sea Storm 155, 52°38'43'N, 173°34'31"W, 393–401 m, 22 Jul 2002, 1 male and 1 indet., USNM 1122881–82; Shishaldin, 53°56'24"N, 179°49'31"E, 318 m, 14 Mar 2000, 1 female and 1 male, USNM 1122549; Shishaldin, 54°07'N, 179°45'E, 366 m, 20 Feb 2000, 1 female and 1 male, USNM 1122544–455; Shishaldin, 54°23'29"N, 179°19'46"E, 413 m, 12 Feb 2000, 1 male, USNM 1122548; Vesteraalen 941–165, 51°34'N, 178°19'E, 470 m, 18 Jul 1994, 1 female and 1 male, USNM 96247; Slear, coll., 51°59'52"N, 176°47'05"E, 241 m, 13 Nov 2000, 1 male, USNM 1122458; University of Washington, 51°32'N, 179°15'W, 278–289 m, 1 Sep 1968, 1 female, USNM 76377; 54°20'15"N, 133°03'19"W, 457–466 m, 1 Sep 2002, 1 female, USNM 1123535; 51°13'43"N, 179°49'31"E, 465–529 m, 13 Jun 2000, 1 male, USNM 1137421.

Colonies usually uniplanar (Fig. 1B), but occasionally multiplanar or arborescent (Fig. 1A, C). Largest specimen examined (USNM 1122542, Fig. 1C) 11 cm tall and 20 cm broad, having a basal diameter of 3 cm, colonies broader than tall not uncommon. Base of colony broadly encrusting. Branching irregularly dichotomous, occasionally anastomotic. Large basal branches circular to elliptical in cross section, but terminal branches have flattened faces, thus rectangular in cross section. Branch tips blunt and rounded. Coenosteum white to light orange, the latter usually having branches with a white core. Coenosteum reticulate-granular in texture, the strips being 0.10-0.14 mm in width, each strip covered with tall (22 µm tall, 9 µm in diameter), slender granules arranged 8-10 across the width of a strip. Faces of distal branches often bear longitudinal ridges (Fig. 2A, D, K), some ridges up to 4 mm in length, sometimes ending distally in what appears to be a dactylopore opening (Fig. 2D).

Pore rows well defined (Fig. 2B), 1.0–1.3 mm in width, and restricted to lateral branch edges, although isolated rows and some irregularities may occur proximally on large colonies. Gastropores linearly arranged in a shallow sulcus, closely spaced (approximately 12–16 per cm), and circular in shape, measuring 0.33–0.41 mm in diameter. Gastropore tubes long and slightly curved, a diffuse ring palisade present near gastrostyle tip, the elements globular and about 30 µm in diameter; tabulae absent. Gastrostyles long, slender, and fragile, up to 1 mm in length and 0.09 mm in diameter, having high H:W ratios up to 8-10. Gastrostyles longitudinally ridged and bear numerous long slender spines up to 0.07 mm in length and 10–12 µm in diameter. U-shaped dactylopore spines arranged on both sides of gastropore row, but often more common on one side than the other, e.g., 18-20 dactylopore spines on one side opposite 28-40 spines on other side. Dactylopore spines up to 0.4 mm tall and 0.25-0.30 mm in width, with a dactylotome width of 0.07-0.08 mm, always directed toward or slightly obliquely to the adjacent gastropore. Dactylostyles absent.

Female ampullae (Fig. 2J) prominent, superficial, hemispherical mounds clustered on branch faces, 1.0–1.5 mm in diameter. Ampullae usually covered by low ridges, either radiating from the central apex or arranged in parallel, longitudinal rows aligned with branch axis. Lateral efferent pores 0.25–0.30 mm in diameter. Male ampullae (Fig. 2K) also superficial mounds, but mostly embedded in coenosteum (internal), also occurring in clusters on branch faces. Male ampullae irregular in shape, often with an apical tip, and smaller than female ampullae (0.35–0.45 mm in diameter).

Among the 26 Recent species of Distichopora (see Cairns et al. 1999; Cairns 2005; and Appeltans et al. 2011: WoRMS database – www.marinespecies.org), the most similar is Distichopora borealis japonica Broch, 1942, described from Sagami Bay, Japan (110 m). Although similar in gross morphology, subspecies japonica differs in coenosteal texture (porcellaneous), and in ampulla shape, each female ampulla having more than one efferent pore and the male ampullae clustered densely in a continuous mat. Also, the dactylotomes of the dactylopore spines are oriented upward to outward (away from the gastropores), not inward toward the gastropores. These differences would argue for an elevation to the species level of this putative subspecies. The observations are based on examination of a fragment of a syntype of Distichopora borealis japonica (USNM 76868) and additional Japanese material deposited at the NMNH (USNM 44198, 44199, 44202, and 44217). Of the 111 specimens examined, 45 are female, 53 male, and 13 indeterminate in gender.

Common in the Aleutian Islands from the Near Islands to Amukta Pass, including Bowers Bank; off Cape Ommaney, Alexander Archipelago, and Dixon Entrance, Queen Charlotte Islands; 53–1267 m, the shallowest record being from Cape Ommaney.

Colonies lamellar, often attaining a large size. Coenosteum reticulate-granular, reddish-orange. Gastro- and dactylopores uniformly distributed on corallum faces, of the axial type. Dactylopore spines circular to elliptical, enclosed by a thin wall for entire perimeter. Dactylostyles absent. Gastrostyles elongate but tabulae absent; a diffuse ring palisade present. Ampullae internal.

The genus is monotypic. According to the molecular analysis of Cairns 2005), rendering the colonies of Distichopora anceps as a “transition” in morphology between the two genera.

Cyclohelia lamellata Cairns, 1991, by original designation.

Known only from the Aleutian Islands and Pribilof Islands, 27–567 m.

The holotype, a dry female colony (USNM 85077, Fig. 1D). Type locality. Off Pribilof Islands, 550 m.

Alaskan Leader 35, 53°01'48"N, 170°06'12"W, 172–178 m, 4 Jun 2002, 1 female, 1 male, USNM 1122491; Alaskan Leader, 54–14, 51°44.4'N, 178°16.7'W, 567–680 m, 11 Jun 2002, 1 female, AB02–0029; Alaska Beauty, 51°42.43'N, 176°56.05'E, 351 m, 3 Feb 2000, 1 female, AB00–15; Delta 5999–8E-5, 52°21.042'N, 179°30.483'W, 115 m, 4 Jul 2003, 3 fragments, AB10–0001; Delta 6000–10D-2, 51°50.8545'N, 179°49.6488'E, 150 m, 5 Jul 2003, 1 indet., AB; Delta 6001–10C-1, 51°52.396'N, 179°46.191'E, 230 m, 5 Jul 2003, 1 female, AB; Delta 6213–12B-1 , 2 and 4, 6 males, AB; Delta, 51°50'55"N, 179°48'35"W, 125 m, 17 Jul 2002, 1 female in alcohol (digitate form), USNM 1122494; North Pacific, 52°04.28'N, 176°05.35'E, 366 m, 1 indet., AB00–28; Ocean Olympic, 52°11.89'N, 176°17.3'E, 366 m, 20 Oct 2000, 1 female (digitate form), USNM 1122513; Pacific Knight 941–121, 51°38'00"N, 178°19'00"W, 0–373 m, 5 Jul 1994, 1 female and 1 male, USNM 96235 and 1122900; Pacific Knight 941–179, 52°00'N, 176°44'E, 0–90 m, 23 Jul 1994, 1 female (intermediate form), USNM 96236; Patricia Lee, 51°18'42"N, 179°30'04"E, 329 m, 20 Oct 2000, 1 male, USNM 1122488; Patricia Lee 51°53.44'N, 179°47.7'E, 298 m, 3 male, SEM stub 1488, AB00–41; Sea Storm 107, 52°10'28"N, 175°14'14"E, 214 m, 8 Jul 2002, 1 female in alcohol, USNM 1123297; Sea Storm 108, 52°11'32'N, 175°17'E, 208 m, 8 Jul 2002, 10 female, 6 male, 8 indet. (digitate form) in alcohol and dry, USNM 1122951, -54, -55, -57, -58, -59, 61, 1123290, 91; Sea Storm 111, 52°16'20"N, 175°59'13"E, 137 m, 9 Jul 2002, 1 male in alcohol, USNM 1122949; Sea Storm 112, 52°15'12"N, 176°10'42"E, 137 m, 9 Jul 2002, 1 indet., USNM 1122946; Sea Storm 116, 52°04'10"N, 177°14'25"E, 87–94 m, 11 Jul 2002, 1 male in alcohol (digitate form), USNM 1122942; Sea Storm 122, 52°02'49"N, 179°25'18"E, 143 m, 13 Jul 2002, 8 female, 4 male, 5 indet., USNM 1122899, 1122948, 1123294–96, -98; Sea Storm 123, 52°10'53"N, 179°37'02"E, 124 m, 13 Jul 2002, 2 male, USNM 1122952; Sea Storm 125, 52°12'53"N, 179°56'49"W, 89–96 m, 13 Jul 2002, 1 male, USNM 112305; Vesteraalen 3, 52°38'13"N, 169°47'14"W, 75–83 m, 22 May 2001, 1 male in alcohol, USNM 1076490; Vesteraalen 941–36, 52°56'N, 169°31'W, 0–227 m, 10 Jun 1994, 1 female, USNM 96237; Vesteraalen 941–46, 53°04'N, 170°09'W, 0–174 m, 12 Jun 1994, 1 female, USNM 96238; Vesteraalen 941–153, 52°10'N, 179°43'E, 0–94 m, 11 Jul 1994, 1 male, USNM 96239; “Vessel" 35, 51°45'48"N, 178°09'47"W, 200–400m, 4 Jun 2000, 2 female and 1 male, USNM 1122493; Renfro, coll., 51°56'35"N, 179°17'58"E, 236 m, 1 female, USNM 1122456; coll. Slear, 51°59'52"N, 176°47'05"E, 241 m, 13 Nov 2000, 1 male (digitate form), USNM 1122457; Petrel Bank, 1 male, 1 indet., USNM 1123540; 51°52.11'N, 179°49.51'W, 27 m, 17 Jul 2002, 1 female (digitate form), USNM 1122492.

This species is not redescribed herein as it was adequately described originally (Cairns 1991) and, being the only species in the genus, conforms to the genus diagnosis above. But, the species was previously known from only two specimens, the type and a specimen sequenced by Lindner et al. (2008), and thus more can be added to its description, including details of the male ampullae, based on the 81 additional specimens reported herein.

Colonies are usually firmly attached to a hard substrate by a robust cylindrical base and stem (Fig. 1H) up to 2.5 cm in diameter, which, at the height of about 2 cm, bifurcates into two lamellae or sheets, each sheet increasing its surface area by folding and undulating its surfaces into a complex three dimensional structure. Large colonies may attain a height of about 8 cm and a width of 10 cm, colonies wider than tall being the norm. However, a subset of colonies from seven stations (see Material Examined), termed the “digitate form”, differ from the typical colony morphology in having dissected plates, resulting in numerous flattened lobes and clavate branches (Fig. 1E). Furthermore, one colony (Fig. 1F) is intermediate between these two extremes, suggesting that these shapes are simply variations of the same species.

Male ampullae (Fig. 3A) entirely internal, and elliptical in shape, the greater axis of the ellipse perpendicular to the branch surface, unlike that of the female ampullae. Male ampullae are up to 0.6 mm in greater diameter and 0.45 mm in lesser diameter, occurring in great concentrations and invariably present on almost any broken surface. Each ampulla communicates to the surface by a circular efferent duct, the duct about 0.07–0.09 mm in diameter, which is surrounded by small inward projecting granules, giving the pore a star-shaped appearance (Fig. 3B–C). Of the 81 specimens examined, 34 are female, 29 male, and 18 indeterminate in gender.

In addition to the type locality off the Pribilof Islands, this species is common throughout the Aleutian Islands from the Rat Islands to the Islands of Four Mountains at 27–567 m, although it was more commonly collected from the western part of this range at depths of 100–300 m. The digitate form is known only from the western Aleutian Islands from 27–366 m.

(emended from Lindner 2005): Colonies uniplanar to slightly bushy; branches round, elliptical, or lamellar in cross section, often robust with blunt tips. Coenosteal texture reticulate-spinose (with wide slits resulting in a spongy texture) or reticulate-granular; exterior surface of dactylopore spines usually inconspicuously longitudinally ridged; coenosteum orange, pink, and white. One species, Errinopora cestoporina, bears numerous perforated mounds on surface. Dactylopores dimorphic, the most common, termed the primary dactylopore spine, is U-shaped and usually robust (thick-walled), occurring randomly, in pseudocyclosystems, or often laterally fusing to form rows or taller terraces that flank rows of gastropores. When dactylopore spines flank both sides of a gastropore row and their dactylotomes are directed toward the gastropores it is termed bilateral or distichoporine; if only one row of spines flank a row of gastropores, then unilateral. If isolated, dactylotomes usually abcauline in orientation. Much smaller flush dactylopores, termed secondary dactylopores, which lack dactylostyles, commonly scattered over coenosteum of many species. Dactylostyles usually well developed, easily seen from external view. Secondary dactylopores much smaller, flush with coenosteum, and lack styles. Gastropores also dimorphic, the primary gastropores being circular in outline, flush with coenosteum (having no lip), and arranged in irregular vertical rows, short horizontal rows, or randomly. Tabulae and ring palisades absent. Gastrostyles lanceolate, covered with longitudinal or oblique, spiny ridges. Smaller secondary gastropores much smaller, having only a small gastrostyle or none at all. Female ampullae superficial hemispheres, often without an obvious efferent pore. Male ampullae usually smaller hemispheres and spongy.

The ten species in this genus are differentiated and compared in both a dichotomous key (see below) and tabular key (Table 1); six of them occur exclusively in the Aleutian Islands. Another species was tentatively assigned to this genus by Cairns (1983b), Errinopora lobata (Nielsen, 1919), a Paleocene fossil from Denmark. This species was re-examined by Bernecker and Weidlich (1990, 2005), based on subsequently collected non-type material from the Faske Formation in Denmark. They noted that whereas the dactylopore spines were typical of Errina or Errinopora, the spines did not contain dactylostyles, and thus resembled Errina more than Errinopora. We have examined the holotype of Labiopora lobata Nielsen, 1919 (GM1782), which is a uniplanar colony 10.2 cm tall and 8.0 cm wide, with branches about 0.5 cm in diameter embedded within a Dendrophyllia matrix. The colony has pores, or broken bulges, of three sizes: small and elongate (75–110 µm in width), medium and round to somewhat quadratic (0.3–0.53 mm wide), and large, round or somewhat triangular (up to 1.7 mm). The former are quite shallow and probably the result of a reticulate coenosteal surface, whereas the medium-sized pores are deep and possibly represent the gastropores, one of which has a cyclosystem-like structure 1.9 mm in diameter. The largest pores appear to be ruptured ampullae. None of them, however, resemble dactylopore spines like those reported by Nielsen (1919) or Bernecker and Weidlich (1990, 2005), suggesting that the species reported by the latter authors is neither Errina nor Errinopora. Likewise, the lack of dactylopore spines in the type of Labiopora lobata precludes it from being Errinopora, and thus we currently suggest an incertae sedis placement of this species until further analysis.

Species within Errinopora are unique with the Stylasteridae in having both dimorphic gastro- and dactylopores, a condition first noted by Fisher (1938) for three Alaskan species but interpreted exclusively as secondary dactylopores. Careful examination of longitudinal sections of several of these pores reveal that they contain not dactylostyles, but rather small gastrostyles. This implies that most species of Errinopora (all but Errinopora fisheri and Errinopora cestoporina Cairns, 1983, see Table 1) have two types of gastrozooids (feeding polyps), a unique case for stylasterids but previously reported for the hydractiniids Stylactaria conchicola (see Namikawa et al. 1992). Secondary gastropores differ from primary gastropores in being narrower and deeper, and in having only a minute or no gastrostyle. All but one species (Errinopora fisheri, see Table 1) also have dimorphic dactylopores: a large type surrounded by a prominent horseshoe-shaped spine, and smaller, flush pores only 40–110 µm in diameter, which do not have dactylostyles and are termed secondary dactylopores.

In comparison to other stylasterid genera, Errinopora is most similar to Gyropora Boschma, 1960, whose only species, Gyropora africana Boschma, 1960, has dactylopore spines and gastropores coordinated in pore rows, as in some species of Errinopora. Errinopora is also similar to Errina Gray, 1835 and Errinopsis Broch, 1935, whose species may also have thick-walled dactylopore spines. None of these genera, however, include species with dactylostyles, as in Errinopora. Among genera with species having dactylostyles, only species of Errinopora, Inferiolabiata Broch, 1951, and Paraerrina Broch, 1942 lack a coordination of gastropores and dactylopores in well-developed cyclosystems (whereas species of Stenohelia Kent, 1870, Stylantheca Fisher, 1931, Stylaster Gray, 1831 and Calyptopora Boschma, 1968 do have both dactylostyles and well-developed cyclosystems). Inferiolabiata differs from Errinopora in many characters, in particular by having thin-walled dactylopore spines (instead of thick-walled) that are markedly truncated at the tip (instead of rounded), whereas Paraerrina Broch, 1942 differs in having delicate dactylostyles (instead of robust) and either flush or only slightly raised dactylopore spines—instead of tall and robust (Cairns 1984, 1991). Errinopora is also one of the few stylasterid genera with species having calcitic, rather than aragonitic, colonies (Thompson and Chow 1955, Lowenstam 1964, Cairns and Macintrye 1992). The only other stylasterid genera with species known to have mostly calcitic colonies are Errinopsis, Errina, and one species of Stylaster—Stylaster verrillii (Dall, 1884) (see Cairns and Macintrye 1992). Within Errinopora, only Errinopora cestoporina, known solely from the Subantarctic Region, is known to have coralla formed by precipitation of aragonite. This result confirms the more general observation of the prevalence of calcitic stylasterids in the North Pacific (Cairns and Macintrye 1992), possibly related to the shallower depth of the Aragonite Saturation Horizon (ASH) in the Region (Guinotte et al. 2006).

In an attempt to investigate phylogenetic relationships, 37 partial mitochondrial rDNA 16S sequences were obtained for the six species of Errinopora from the Aleutian Islands, including the holotypes of Errinopora dichotoma, Errinopora disticha, Errinopora fisheri and Errinopora undulata. Based on Lindner et al. (2008) included Errinopora nanneca (specimen USNM1027820) and Errinopora zarhyncha Fisher, 1938 (specimen USNM1071915), and shows that these species diverged only about 4 million years ago. Moreover, the same study shows that Cyclohelia lamellata Cairns, 1991 and Distichopora borealis Fisher, 1938, two sympatric Alaskan stylasterids that are also clearly distinguishable with marked morphological differences (see above), may have diverged as recently as 1 million years ago. These results indicate that part of stylasterid species diversity in Alaska may have diverged only within the past 1-4 million years and, at least for Errinopora, the results presented herein show that despite the marked morphological differences, some species are not recovered as reciprocally monophyletic lineages (Baum and Shaw 1995, Avise 2000) using mitochondrial rDNA 16S.

Errina pourtalesii Dall, 1884, by original designation.

North Pacific: Aleutian Islands, Kurile Islands, Sea of Okhotsk, Sea of Japan, off California. Subantarctic: off Tierra del Fuego, 40–658 m.

Holotype: Pacific Knight 204, a dry female colony, USNM 1123526 (Fig. 5A). Paratype: Sea Storm 36, 53°05'45"N, 171°41'56"E, 458 m, 1 branch, USNM 1157073. Type locality. 53°06'N, 171°42'E (off Attu Island, Aleutian Islands), 455 m, 31 Jul 1994.

Named in honor of Walter K. Fisher, who wrote the original revision of the Aleutian Island stylasterids (Fisher 1938) and described the genus Errinopora (Fisher, 1931).

Holotype.

Holotype (Fig. 5A) uniplanar with a secondary flabellum at mid-height, 9 cm in height and 6.5 cm in width, with a basal branch diameter of 10 × 7.5 mm. Branches circular to slightly elliptical in cross section and irregularly dichotomous, small-diameter branches often diverging from larger main branches; branch anastomosis absent. Coenosteum reticulate-granular in texture, the strips being 80-90 µm in width and covered with small granules 5-15 µm in diameter; strips bordered by slits 40-45 µm wide. Coenosteum light orange.

Dactylopore spines favor one face of corallum over the other, arranged in abcauline, crescent-shaped terraces flanking one or two gastropores (Fig. 6A-D). Terraces sometimes almost completely surround a gastropore (Fig. 6C-D), resembling a cyclosystem of 1.5 mm diameter with an adcauline diastema, much as in Stylaster, but isolated dactylopore spines also fairly common, especially near base of colony. Dactylopore terraces quite thin (0.35 mm) and up to 1.5 mm in height, and, although laterally fused, the individuality of each dactylopore spine is subsumed into the more continuous terrace structure; compound dactylopore spines absent; exterior surface of spines longitudinally ridged. Terraces often horizontally oriented on branches, and slightly flared around gastropore(s). Dactylotomes not slit-shaped as in most other Errinopora, but instead small elliptical pores about 0.27 mm long and 0.15 mm in width occurring only near tips of spine structure; dactylotomes always directed toward a gastropore. Dactylostyles small, about 50 µm in width, having stubby elements up to 25 µm in length and 10-15 µm in diameter. Secondary dactylopores absent.

Gastropores circular, flush with coenosteum, 0.3-0.5 mm in diameter, being fairly consistent in size; gastropores isolated, not arranged in rows; secondary gastropores absent. Gastropore tube cylindrical, but with a slight medial constriction; often a ring palisade is present, the elements 50 µm tall and 15-25 µm in diameter. Gastrostyle squat, an illustrated one being 0.33 mm tall and 0.29 mm in diameter (Fig. 6I). Gastrostyles covered with longitudinal anastomosing ridges as consistent with the genus. Female ampullae (Fig. 6D) hemispherical but often irregular in shape due to protruding dactylopore spines. Female ampullae 1.0–1.2 mm in diameter; efferent pores not observed. Male ampullae unknown.

Even though represented by only one specimen, Errinopora fisheri can be distinguished from other Alaskan congeners by the distinctively terraced arrangement of its dactylopore spines, its small elliptically-shaped dactylotomes, its squat gastrostyles, and its constricted gastropore tube with a ring palisade (see Dichotomous Key and Table 1). Most of these features, however, are shared with Errinopora cestoporina, a species known only from Burdwood Bank and off Tierra del Fuego at 359-384 m. Errinopora cestoporina differs in having differently shaped ampullae, a different corallum color (white), small perforated mounds covering the coenosteum, and a differently shaped gastrostyle.

Known only from Aleutian Islands: off Attu Island; 455-458 m.

Holotype: Vessel and collector unknown, Amukta Pass, 350–500 m , 1 dry female colony 12 cm tall, USNM 1123527 (Fig. 5C). Paratypes: Vessel and collector unknown, Amukta Pass, 356–640 m, 1996, 1 dry female colony, USNM 1123528; south of Semisopochnoi Island, 366 m, 1 dry female colony, USNM 88371. Type locality. Aleutian Islands: Amukta Pass, 350–500 m.

The specific name undulata (from the Latin undulatus, meaning wavy) refers to the sinusoidal margin of the lamellate colonies.

Types.

Colonies lamellate, but wavy in construction resulting in a continuous, thin (1.7–2.0 mm thick), sinusoidal distal edge. Largest colony (USNM 1123528, Fig. 5F) 13 cm tall and 15 cm wide, with a massive basal branch 4.5 × 2.5 cm in diameter; holotype (Fig. 5C) smaller and less intact, measuring 12 cm tall and 11 cm wide, with a basal branch 3.5 × 2.8 cm in diameter. Parasitic spionid worm tubes found in only one colony (USNM 1123528). Coenosteum quite porous, consisting of a reticulum of narrow spiny strips separated by even wider slits, the spines being 10-15 µm in diameter. Coenosteum orange.

Dactylopore spines occur equally on both branch faces, but less abundant toward corallum base. Most dactylopores clustered around isolated gastropores in pseudocyclosystems, 3–5 spines surrounding one pore (Fig. 7B). Pseudocyclosystems most common toward base of colony but also occur frequently on more distal parts of corallum where they are interspersed with short, transverse rows of dactylopore spines that border the distal margins of one or more gastropores, their dactylotomes facing upward (abcauline) toward the gastropore; compound dactylopore spines absent. Dactylopore spines fairly short (rarely taller than 0.25 mm), 0.40–0.45 mm in width, and thin walled, the majority of width being the dactylotome; dactylopore spine walls longitudinally ridged. Dactylostyles robust (Fig. 7I–J), up to 0.12 mm in width, consisting of cylindrical elements up to 72 µm in length and 15 µm in diameter. Secondary flush dactylopores common, about 75 µm in diameter.

Gastropores circular, flush with coenosteum, and 0.3–0.45 mm in diameter; secondary gastropores about 0.19 mm in diameter. Gastropore tubes short and lack a ring palisade. Gastrostyles lanceolate, the figured style (Fig. 7G) 0.54 mm in height and 0.29 mm in diameter, covered with longitudinal anastomosing spiny ridges.

Female ampullae (Fig. 7A–B) irregularly-shaped, flattened hemispheres up to 1.6 mm in diameter. Efferent pores not observed. Male ampullae unknown.

. Errinopora undulata is quite similar to the lamellate form of Errinopora nanneca, but differs in a number of points, one being its colony form, which is a continuous wavy sheet of corallum, whereas that of Errinopora nanneca is more like a series of smaller dissected flat blades of a larger plate. Errinopora undulata also has shorter (0.25 vs 0.4 mm) and thin-walled (vs thick-walled) dactylopore spines, and larger gastropores (0.45 mm vs 0.20 mm in diameter) (see Dichotomous Key and Table 1).Of the 247 known stylasterid species (Appeltans et al. 2011: WoRMS database: www.marinespecies.org) only five have adopted a lamellate corallum shape, four of these occurring in the Aleutian Islands (Cyclohelia lamellata, Stylaster repandus, Errinopora nanneca, and Errinopora undulata), the fourth being the Hawaiian Distichopora anceps Cairns, 1978.

Known only from the Aleutian Islands: Amukta Pass and south of Semisopochnoi Island; 350–640 m (unconfirmed).

Holotype: a dry female colony 10 cm in height, coll. Renfro, USNM 1123524 (Fig. 5D). Paratypes: also from type locality, 1 female, USNM 1123521; Alaskan Leader 35, 53°01'48"N, 170°06.62'W, 172–178 m, 4 Jun 2002, 2 male, USNM 1123525; Alb-3480, 52°06'N, 171°45'W, 518 m, 8 Jul 1893, 2 males in alcohol, USNM 43768; Alb-3480, see above, 1 male, USNM 1148212 (ex USNM 52247, paratype of Errinopora zarhyncha); 52°03'26"N, 179°12.34'E, 475 m, 27 Apr 2000, 1 male, USNM 1123523; 51°52'46"N, 179°17'24"E, 536 m, 16 Jul 2000, 2 female, USNM 1123522. Type locality. 51°53'12"N, 179°17.40'E (west of Semisopochnoi I., Petrel Bank), 530 m.

Etymology. The specific name disticha (from the Greek distichos, meaning “of two rows") refers to the short distichoporine pore rows of this species.

Material examined. Types.

Description. Colonies uniplanar to multiplanar, consisting of cylindrical to highly compressed branches, the greater axis of compressed branches oriented in plane of colony flabellum and reaching up to two times length of lesser axis. Branching dichotomous and non-anastomotic, terminating in blunt tips and forming U-shaped axils between branching. Holotype (Fig. 5D) 10 cm tall and equally wide, with a basal branch diameter of 22 × 20 mm; largest specimen (USNM 1123523) 13.5 cm in height. Parasitic spionid polychaete tubes found in only one corallum (USMM 1123525). Coenosteum typical for the genus: reticulate spinose, the narrow strips separated by broad porous slits, resulting in a very porous surface. Coenosteum light orange; branch cores white or lighter orange.

Dactylopore spines mostly arranged in long meandering distichoporine (bilateral) rows of up to 18 laterally fused spines (Fig. 8A-B). Two rows or terraces of dactylopore spines usually flank each gastropore row, the dactylotomes facing the gastropore; however, the number of dactylopore spines is often unequal on either side of a pore row and are occasionally absent from one side. Toward corallum base, pore rows decrease in length, often resulting in a single gastropore surrounded by 3–6 dactylopore spines approximating a pseudocyclosystem. Dactylopore spines fairly short (0.5–0.9 mm in height) and thick-walled, the dactylotome consisting of one-third to half width of spine; compound dactylopore spines common. Dactylostyles robust, up to 75 µm in width, consisting of cylindrical elements up to 53 µm in length and 5–10 µm in diameter; exterior surface longitudinally ridged. Secondary dactylopores, which lack styles, very common on coenosteum, especially back sides of dactylopore spines, these pores being circular, flush with the surface, and measure about 75–110 µm in diameter.

Gastropores circular, flush with coenosteum, and variable in size, ranging from 0.3–0.7 mm in diameter, both size classes often adjacent to one another. Gastropores usually closely spaced and unilinearly arranged in a shallow sulcus created by adjacent dactylopore spine terraces. Gastropore tubes cylindrical, fairly shallow, and lack a ring palisade; secondary gastropores 0.19–0.30 mm in diameter. Gastrostyles lanceolate but somewhat stout, the figured symmetrical style (Fig. 8H–I) being 0.49 mm in height and 0.36 mm in diameter, however, many gastrostyles are asymmetrical, being elliptical to flattened in cross section. Gastrostyles bear longitudinal, spiny, anastomosing ridges, and fill most of gastropore cavity.

Female ampullae (Fig. 8A–B) hemispherical to somewhat flattened (1.3–1.5 mm in diameter), their basal perimeter often slightly undercut, and often with an irregular or ridged surface. Discrete efferent pores never observed. Male ampullae small, porous, hemispherical blisters 0.4–0.6 mm in diameter, often occurring in great concentrations on coenosteum.

Errinopora disticha is the only Alaskan Errinopora species to have its dactylopore spines arranged bilaterally in distichoporine rows flanking a row of gastropores, however two other species have a distichoporine arrangement: Errinopora pourtalesii (California) and Errinopora stylifera (Japan to Okhotsk Sea) (see Dichotomous Key and Table 1). Errinopora disticha differs from those two species in having reticulate-spinose coenosteum (vs reticulate-granular), and flattened gastrostyles and branches. Of the 10 specimens examined, 4 are female and 6 male.

Known only from the Aleutian Islands: off Petrel Bank, Amukta Pass, and off Four Kings Islands; 178-536 m.

Holotype, Alb-3480, a dry male colony 14 cm in height, USNM 42874 (Fig. 5E). Paratypes: Alb-3480, 3 dry female branches, USNM 52247; Alb-3480, 1 branch, CAS 28186. Type locality. Alb-3480: 52°06'N, 171°45'W (Amukta Pass, Aleutian Islands), 518 m.

Shishaldin, 53°56'24'N, 179°49'31"E, 318 m, 14 May 2000, 1 male, USNM 1123447; Shishaldin, 54°54'05"N, 178°37.27'E, 410 m, 11 Feb 2000, 3 female branches, and SEM stubs 1542–43, USNM 1123448; Vesteraalen 941–59, 52°02'00"N, 172°12'W, 658 m, 14 Jun 1994, 3 branches of a female colony, both dry and in alcohol, USNM 96234; Vesteraalen 941–62, 51°58'N, 172°40'W, 207 m, 15 Jun 1994, 1 female, USNM 96233; Vesteraalen, 51°13'17"N, 179°05'57"E, 488 m, 4 Jun 2000, 1 male, USNM 1071915; 51°13'43"N, 179°49'31"E, 465–529 m, 13 Jun 2000, large male colony, USNM 1123446; Types.

Colonies uniplanar or multiplanar, robust, with fairly close dichotomous branching, leaving little space between branches; branch anastomosis occurs but uncommon. Largest colony 26 cm in height and 27 cm in width, with a massive basal branch 4.3 cm in diameter (USNM 1123446). Branches circular to slightly flattened in cross section, attenuating to thick (7–15 mm in diameter), blunt tips. Parasitic spionid polychaete worms form tubes along branch axes in two colonies (USNM 96233, 96234), the tubes Fig. 8 in cross section. Coenosteum quite porous in texture (Fig. 9E–H), consisting of a reticulum of thin (25 µm), spinose ridges, separated by wide slits or series of pores. This texture also present on ampullae and dactylopore spines, in the latter the coenosteal strips forming longitudinal ridges. Coenosteum orange.

Dactylopore spines occur on all branch surfaces and are quite variable in orientation, sometimes forming rows of 10–13 spines laterally fused into a short tier on one side of a pore row (unilaterally), the dactylotomes usually facing upward (abcauline), but dactylopore spines also oriented with their dactylotomes facing downward (adcauline) or laterally, and occasionally are isolated; compound dactylopore spines common. Dactylopore spines quite large and thick-walled, up to 3 mm in height and 1.5 mm in width, the dactylotome occupying one-fourth to one-third width of spine; exterior surface longitudinally ridged. Small, circular, flush secondary dactylopores, measuring only 0.08–0.11 mm in diameter, occur on walls of dactylopore spines, often several on each spine. Whereas dactylopore spines are quite large, dactylostyles are small and thin, only about 30–35 um in width, bearing short spines up to 23 µm in length and 14 µm in diameter.

Gastropores circular and quite variable in size, up to 1.1 mm in diameter, often arranged linearly in valleys created by adjacent rows of dactylopores. Large gastropores often sit directly adjacent to much smaller ones; secondary gastropores about 0.38 mm in diameter. Gastropore fairly shallow, lacking a ring palisade, affording an easy view of base of pore, as the gastrostyle occupies only a small part of gastropore cavity. Gastrostyles lanceolate and slender, up to 0.9 mm in height, and bear longitudinal anastomosing ridges, the gastrostyle size commensurate with diameter of gastropore tube.

Female ampullae inconspicuous (Fig. 9J) and not common, rarely seen in cross section branch fracture. Female ampullae hemispherical, often overshadowed by tall dactylopore spines or becoming incorporated into dactylopore spines. Efferent pores elusive; when detectable they are lateral in position, and about 0.7 mm in diameter, but more often a spent female ampulla lacks its upper half or is simply a crater in the coenosteum, a function of its thin, porous coenosteal cover. Male ampullae equally inconspicuous (Fig. 9C), roughly hemispherical, highly porous, and only about 0.6–0.7 mm in diameter.

Errinopora zarhyncha is one of three species in the genus having a predominantly unilateral arrangement of dactylopore spines in which only one row of laterally fused spines (usually the proximal row) have their dactylotomes facing a gastropore or gastropore row, the other species being Errinopora nanneca and Errinopora dichotoma (see Dichotomous Key and Table 1). Errinopora zarhyncha differs from the other two species in having very tall dactylopore spines, relatively small dactylostyles, large robust colonies, and gastropore tubes that are much larger than their gastrostyles (see Dichotomous Key and Table 1). Naumov (1960) reported this species from the Kurile Islands, but based on his description in which he reports gastropore diameters of only 0.20-0.25 mm and dactylopore spines only 0.6 mm in height, we conclude that he is referring to a different, and as yet unknown species. Of the 8 lots of specimens examined, 4 are female, and 4 male. Coralla were determined to be calcitic by Thompson and Chow (1955) and Cairns and Macintrye (1992).

Endemic to Aleutian Islands in a somewhat disjunct distribution: Amchitka Pass, Bowers Bank, and off Seguam Island; 207-658 m.

Holotype: Alb-3599, a dry female colony 13 cm in height, USNM 42875 (Fig. 5B). Paratypes: Alb-3599, 6 colonies, including that figured by Fisher (1938: plate 67), 4 female, 1 male, 1 indet., all dry, USNM 52263. All other specimens mentioned by Fisher from Alb-3599 and 4777 are expressed excluded from type status according to ICZN (1999) article 72.4.6. Type locality. Alb-3599: 52°05'N, 177°40'E (off Kiska Island, Rat Islands, Aleutian Islands), 101 m, 9 Jun 1894.

Material examined. Alb-3480, 52°06'N, 171°45'W, 517 m, 8 Jul 1891, 1 indet., part of type series of Errinopora zarhyncha, ex. USNM 52247; Alb-3599, type locality, 8 female, 8 male, USNM 52248; Alb-4777, 52°11'N, 179°49'E, 95 m, 5 Jun 1906, 11 female, 7 male, USNM 44070, 52249, 60299, and 62715; Alaskan Leader 35, 53°01'48"N, 170°06'12"W, 172–178 m, 4 Jun 2002, 1 female, 1 male, USNM 1123451 and 1123532; Alaskan Leader 54, 51°45'48"N, 179°06'08"E, 90–467 m, 11 Jun 2002, 1 female, USNM 1123378; Delta, 51°13'30"N, 179°53'17" E, 40 m, 16 Jul 2002, 1 indet. in alcohol, USNM 1123377; Delta 5599, 52°33.47'N, 179°26.44'E, 225 m, 15 Jul 2002, 1 male, USNM 1123452; Delta 5605, 51°50'55"N, 179°48'13"W, 125 m, 17 Jul 2002, 1 male, 4 indet., USNM 1123450 and 1123462; Delta 5607, 51°23'57"N, 179°48'35"W, 182 m, 16 Jul 2002, 1 female, USNM 1123459; Delta 5620, 51°57'40"N, 176°00'42"E, 150 m, 24 Jul 2002, 2 female with fragments in alcohol, USNM 1027820 and 1123510; Delta 5622, 51°57.5'N, 176°50.1'W, 140 m, 24 Jul 2002, 2 female, 1 male, and fragments in alcohol, USNM 1123468, 1123472, and 1123472; Delta 5625, 51°57.7'N, 176°50.2'W, 130 m, 25 Jul 2002, 1 female, USNM 1123473; MF 833–47, 51°55'36"N, 176°52'48"W, 201 m, 5 Aug 1983, 1 female and 1 male, USNM 77049; MF 833–49, 52°00.2'N, 176°21.4'W, 115 m, 5 Aug 1983, 1 male in alcohol, USNM 77031; MF 833–56, 52°02'06"N, 176°22'36"W, 249 m, 6 Aug 1983, 1 female, USNM 77044; MF 833–69, 52°02.8'N, 179°27.2'E, 63 m, 25 Aug 1983, 1 indet., in alcohol, USNM 77030; Pacific Knight 941–61, 52°17'N, 173°06'W, 0–143 m, 17 Jun 1994, 1 female, USNM 96254; Sea Storm 86, 51°36'21"N, 176°17'39"W, 345 m, 3 Jul 2002, 1 female in alcohol, USNM 1123475; Sea Storm 92, 51°33'34"N, 177°40'W, 367 m, 4 Jul 2002, 3 female, 3 male, USNM 1123529, 1123469–70, and 1123376; Sea Storm 100, 51°42'59"N, 175°47'07"E, 86 m, 7 Jul 2002, 1 indet., in alcohol, USNM 1123520; Sea Storm 105, 52°08'59"N, 175°06'47"E, 201 m, 8 Jul 2002, 1 indet. in alcohol, USNM 1123519; Sea Storm 108, 52°11'32"N, 175°17'E, 208 m, 8 Jul 2002, 1 male in alcohol, USNM 1123517; Sea Storm 111, 52°16'20"N, 175°59'13"E, 137 m, 9 Jul 2002, 1 indet. in alcohol, USNM 1123518; Sea Storm 112, 52°15'12"N, 176°00'42"E, 137 m, 9 Jul 2002, 1 indet. in alcohol, USNM 1123512; Sea Storm 114, 52°02'29"N, 177°39'E, 130 m, 10 Jul 2002, 1 male, USNM 1123515; Sea Storm 115, 52°04'16"N, 177°19'04"E, 165 m, 10 Jul 2002, 2 indet. in alcohol, USNM 1123474 and 1123513; Sea Storm 116, 52°04'10"N, 177°14.4'E, 87–94 m, 11 Jul 2002, 5 male, 1 indet., USNM 1123516; Sea Storm 118, 52°00'14"N, 177°19'04"E, 104–111 m, 11 Jul 2002, 2 female, 2 male, USNM 1123375 and 1123471; Sea Storm 122, 52°02'49"N, 179°25'18"E, 143 m, 13 Jul 2002, 1 indet., USNM 1123511; Sea Storm 126, 52°13'22"N, 179°49'26"W, 115 m, 13 Jul 2002, 1 female in alcohol, USNM 1123466; Sea Storm 128, 52°03'22"N, 179°48.13'W, 242 m, 14 Jul 2002, 1 female in alcohol, USNM 1123374; Sea Storm 157, 52°12'35"N, 172°12'20"W, 348 m, 23 Jul 2002, 1 female, USNM 1123467; Vesteraalen 941–50, 52°34'N, 170°40'W, 0–88 m, 13 Jun 1994, 3 female, 3 male, USNM 96252 and 1138188; Vesteraalen 941–59, 52°12'N, 172°12'W, 0–360 m, 14 Jun 1994, 3 male, USNM 96251 and 1123514; Vesteraalen 941–61, 52°05'N, 172°26'W, 0–156 m, 15 Jun 1994, 5 female, USNM 96253; Vesteraalen 941–151, 52°11'N, 179°44'E, 0–151 m, 10 Jul 1994, 1 indet., USNM 96257; Vesteraalen 941–153, 52°10'N, 179°43'E, 0–94 m, 10 Jul 1994, 1 female, 4 indet., USNM 96531; Vesteraalen 941–154, 52°04'N, 179°47'E, 0–254 m, 11 Jul 1994, 1 male, USNM 96258; Vesteraalen 941–163, 51°37'N, 178°25'E, 0–155 m, 18 Jul 1994, 1 female, 1 male, USNM 96256; Vesteraalen 941–185, 52°04'N, 176°30'E, 0–91 m, 24 Jul 1994, 1 male, USNM 96255;Vesteraalen 3, 52°37'48"N, 169°47'16"W, 80 m, 21 May 2001, 1 female in alcohol, USNM 1123368; Gulf of Alaska, 219 m, 1 indet., USNM 77414; Renfro, coll., 52°02'17"N, 179°25'21"E, 236 m, 5 Apr 2000, 1 female, USNM 1123455; 52°18'N, 179°48'35"W, 490 m, 28 May 2000, 1 indet., USNM 1123457.

Colonies quite variable in shape. Most colonies examined uniplanar, consisting of irregularly dichotomous, non-anastomotic branching (e.g., the holotype, Fig. 5B). The opposite extreme is multilobate and multiplanar colonies (Fig. 5H), composed of thin blades of corallum set in a three dimensional arrangement. Virtually all intergrades in colony shape were observed, including some having both large flattened lobes and slender branches (Fig. 5G). Tallest colony examined (USNM 96252) 21 cm in height with a basal branch diameter of 3.5 cm, but a broken colony having a basal diameter of 4 cm (USNM 1123516) implies an even larger size. Although distal branches often circular in cross section, more often they are somewhat compressed in branching plane. Parasitic spionid polychaete worms often form tubes along axis of branches, Fig. 8 in cross section. Coenosteum reticulate-spinose, the narrow strips only about 60 µm wide and bordered by slits of equal width, each strip bearing irregularly unilinearly arranged spines, altogether producing a porous or rough coenosteal texture. Coenosteum light orange to light pink.

Dactylopore spines isolated or arranged in transverse to oblique rows on distal branches, their dactylotomes facing upward (abcauline), their edges often fusing with edges of adjacent dactylopore spines. On more proximal branches and the basal branch, dactylopore spines fewer in number, and arranged in pseudocyclosystems, short rows, isolated, or as circles around small islands of 2–5 gastropores. Dactylopore spines strongly favor one face of corallum, and are much less common on opposite face. Dactylopore spines relatively small, only about 0.4 mm in maximum height and 0.30-0.35 mm in width, the dactylotome occupying middle third. Small (40–115 µm in diameter) secondary dactylopores flush with coenosteum common. Outer surface of dactylopore spines prominently ridged; inner surface bears a moderately robust dactylostyle (40–50 µm in width, Fig. 10J–K) composed of elements up to 18 µm tall and 7 µm in diameter.

Gastropores circular and flush with coenosteum, 0.15-0.44 mm in diameter, the average about 0.20 mm. Gastropore tube cylindrical, without a ring palisade. Gastrostyles lanceolate, up to 0.55 mm in height, bearing spinose longitudinal, sometimes anastomosing, ridges that themselves bear small spines up to 32 µm long and 8 µm in diameter. Smaller secondary gastropores, lacking gastrostyles, also present, these 0.11–0.19 mm in diameter.

Female ampullae (Fig. 10C) large hemispheres 1.1–1.8 mm in diameter, occurring fairly densely and equally on both corallum faces. Dactylopore spines often occur on female ampullae. Efferent pores rarely observed, but are lateral and up to 0.5 mm in diameter. Male ampullae smaller mounds 0.4–0.7 mm in diameter, clustered, and somewhat irregular in shape. Both types of ampullae porous, like the coenosteum.

Errinopora nanneca is one of three species in the genus having a predominantly unilateral arrangement of dactylopore spines in which only one row of laterally fused spines (usually proximal to gastropores) have their dactylotomes facing a gastropore or gastropore row, the other species being Errinopora zarhyncha and Errinopora dichotoma (see Dichotomous Key and Table 1). Errinopora nanneca is distinguished from Errinopora zarhyncha in the account of the latter species, but differs from Errinopora dichotoma in having shorter dactylopore spines and smaller gastropores, uniplanar colonies, and prominently ridged dactylopore spines. Of the 126 specimens examined, 58 are female, 42 male, and 26 indeterminate in gender. The corallum was found to be 100% calcitic according to Cairns and Macintrye (1992).

Aleutian Islands from eastern Rat Islands to Islands of Four Mountains, including Petrel Bank; 40-517 m.

Holotype: Dominator 971–73, 1 alcohol-preserved male colony 11.5 cm in height, USNM 1123508 (Fig. 11D). Paratypes: Alaskan Leader, 53°01'42"N, 170°05.99'W, 200–400 m, 4 Jun 2000, 1 male, USNM 1123507; Alaskan Leader 35, 53°01'48"N, 170°06'12"W, 172–178 m, 4 Jun 2002, 1 female, 1 male, USNM 1137600; Dominator 971–73, topotypic, 1 dry branch, male, USNM 1148143. Type locality. Dominator 971–73, 52°33'10"N, 179°25'18"E (off northwestern Petrel Bank), 217 m, 26 Jun 1997.

The specific name dichotoma, meaning “in two parts" (from the Greek dicha, meaning “in two" and tomos, meaning “part" or “slice"), referring to the dichotomous branching mode of this species.

Types.

Colonies three dimensional, robust, and sparsely branched, branching equally and widely dichotomously, resulting in broad U-shaped axils; branch anastomosis absent. Largest colony (holotype, Fig. 11D) 11.5 cm in height, with a basal branch diameter of 16 × 20 mm. Branches circular to elliptical in cross section, attenuating to thick (7–8 mm in diameter), blunt tips; tips of most branches missing (broken) from type material. As in most species of Errinopora, coenosteum quite porous (Fig. 12F–I), composed of a reticulum of thin, spinose strips separated by wide slits or series of pores, the spines being up to 55 µm in height and 15–24 µm in diameter. Coenosteum orange, branch cores being white.

Dactylopore spines occur on all branch surfaces and quite variable in orientation (Fig. 12B), sometimes forming transverse or longitudinal rows of up to 7 laterally fused spines, spines sharing the same laterally fused row sometimes oriented in opposite directions, their dactylotomes facing in opposite directions. Isolated dactylopore spines also present. Dactylopore spines of moderate size and thick-walled, up to 1.2 mm in height and 1.1 mm in width, the dactylotome occupying one-fourth to one-third width of spine. Small (80 µm diameter), circular secondary dactylopores common. Dactylostyles robust (Fig. 12C, L–M), each about 0.125 mm in width, composed of elements up to 40 µm in height and 10-12 µm in diameter.

Gastropores circular, sometimes arranged in rows, otherwise randomly arranged, 0.3-0.5 mm in diameter; pores lack a ring palisade. Secondary gastropores (Fig. 12C, lower) 0.22–0.30 mm in diameter. Gastrostyle occupies most of gastropore cavity. Gastrostyles lanceolate, up to 0.5 mm in height, bearing longitudinal, anastomosing, spinose ridges.

Intact female ampullae never observed, but coenosteal depressions 1.0–1.1 mm in diameter are common in one specimen, these presumed to be spent female ampullae. Male ampullae small, porous hemispheres 0.5–0.6 mm in diameter.

Errinopora dichotoma is one of three species in the genus having a predominantly unilateral arrangement of dactylopore spines in which only one row of laterally fused spines (usually proximal to gastropores) have their dactylotomes facing a gastropore or gastropore row, the other species being Errinopora nanneca and Errinopora zarhyncha. Errinopora dichotoma is compared to those species in their respective accounts and in the Dichotomous Key and Table 1. Of the five specimens examined, 1 was presumed to be female and 4 male.

Endemic to Aleutian Islands: off Petrel Bank, off Islands of Four Mountains; 178–217 m (Cairns 1992; Appeltans et al. 2011).

Colonies branching in a flabellum or a bush shape (in only one case lamellate). Coenosteum usually reticulate-granular but may be linear-imbricate; coenosteum of many colors and hardness. Gastro- and dactylopores arranged in conventional cyclosystem arrangement, with only one gastrostyle per cyclosystem; pores of the peripheral type; supernumerary dactylopores often present. Cyclosystems arranged on branch edges and/or on corallum faces, or uniformly on all branch surfaces, but not unifacially. Gastropore tube single-chambered, but may be constricted by a ring palisade. Dactylostyles present. Ampullae usually superficial.

The genus and its various grouping are discussed by Cairns (1983b) and a key to all stylasterid genera, including the groups of Stylaster, is provided by Cairns (1992). Currently there are 80 recognized Recent species and 7 fossil species (Appeltans et al. 2011: WoRMS data base: www.marinespecies.org). It is by far the most species-rich and diverse genus of the stylasterids.

Madrepora roseus Pallas, 1766, by subsequent designation (Milne Edwards and Haime 1850: xxii), a member of Group B.

Oligocene to Recent: cosmopolitan from depths of 0-2010 m (Cairns 1992; Appeltans et al. 2011).

Allopora brochi: Alb-4777: The dried holotype is deposited at the USNM (43264, also SEM stub 1497), measuring 9 cm in height (Fig. 11A); a paratype is also deposited at the CAS (28183). Type locality. Albatross 4777: 52°11'N, 179°49'E (Petrel Bank, Aleutian Islands), 79–95 m.

Allopora abei: Holotype, dry, Dept. of Mineral Sciences, Tohoku University (1001). Type locality. Off the Aleutian Islands, exact locality and depth unknown.

Holotype, USNM 43264; Alb-3599, 52°05'N, 177°40'E, 101 m, 9 Jun 1894, 1 female, USNM 76814 (part of type lot of Stylaster campylecus); Alb-4779, 52°11'N, 179°57'W, 99–102 m, 5 Jun 1905, 1 female, USNM 44069; Alaskan Leader 35, 53°01'42"N, 170°05'59"W, 200–400 m, 4 Jun 2000, 1 male, USNM 1122516; Delta 5607, 51°23'02"N, 179°01'38"W, 126 m, 18 Jul 2002, 1 female, USNM 1122486; Delta 5620, 51°57'40"N, 176°50'01"W, 150 m, 24 Jul 2002, 5 female, 5 males, 5 indet., some in alcohol, USNM 1112304, 1123302, 1123304, 1123345–1123350; Delta 5622, 51°57'37"N, 176°49'58"W, 140 m, 24 Jun 2002, 2 indet., USNM 1123303; Delta 5624, 51°47'40"N, 176°49'58"W, 140 m, 25 Jun 2002, 1 male, USNM 1123300; Delta 5625, 51°57'42"N, 176°50'01"W, 156 m, 25 Jun 2002, 1 female, 1 indet., USNM 1027821; Delta 6000–10D-12, 51°50.828'N, 179°49.674'E, 112 m, 5 Jul 2003, 1 female, AB10–0002; Dominator 971–73, 52°33'10"N, 172°20'58"W, 217 m, 6 Jun 1997, 1 male in alcohol, USNM 1123366; Dominator 971–135, 51°37'22"N, 178°35'E, 163 m, 14 Jul 1997, 1 female, USNM 1123364; Let's Go, 51°57'N, 178°11'E, 0–247 m, 30 Aug 1986, 3 males, USNM 96259; MF 801–70, 52°03'24"N, 179°25'06"E, 174 m, 29 Jul 1980, 1 female, USNM ; MF 833–47, 51°55'36"N, 176°52'48"W, 201 m, 5 Aug 1983, 1 male, USNM 77048; Ocean Olympic, 52°04'31"N, 177°12'28"E, 293 m, 4 Mar 2000, 1 male, USNM 1122540; Pacific Knight 941–36, 53°02'N, 170°13'W, 0–178 m, 11 Jun 1994, 8 male, USNM 96265, 96525, and 96542; Pacific Knight 941–37, 52°17'N, 170°40'W, 0–155 m, 12 Jun 1994, 1 male, USNM 96269; Pacific Knight 941–40, 52°41'N, 170°49'W, 0–126 m, 12 Jun 1994, 1 male, 1 indet., USNM 96270 and 96534; Pacific Knight 941–42, 52°55'N, 170°24'W, 0–225 m, 13 Jun 1994, 1 male, USNM 96522; Pacific Knight 941–49, 52°46'N, 171°45'W, 0–340 m, 14 Jun 1994, 1 female, USNM 96521; Pacific Knight 941–121, 51°38'N, 178°19'W, 0–375 m, 5 Jul 1994, 3 female, USNM 96262; Pacific Knight 941–204, 5306'N, 171°42'E, 9–455 m, 31 Jul 1994, 1 female, USNM 96523; Sea Storm 90, 51°36'30"N, 177°10'48"W, 217 m, 4 Jul 2002, 1 male in alcohol, USNM 1123009; Sea Storm 91, 51640'51"N, 177°10'49"W, 82 m, 4 Jul 2002, 1 male, USNM 1123021; Sea Storm 100, 51°42'59"N, 175°47'07"E, 86–94 m, 7 Jul 2002, 1 indet. in alcohol, USNM 1076928; Sea Storm 101, 51°45'27"N, 175°40'06"E, 83 m, 7 Jul 2002, 1 female, 2males, USNM 1123024, -26, -27; Sea Storm 105, 52°08'59"N, 175°06'47"E, 201 m, 8 Jul 2002, 1 male, USNM 1123023; Sea Storm 111, 52°16'20:N, 175°29'13"E, 137 m, 9 Jul 2002, 1 male and 1 female in alcohol, USNM 1123000, 1123013; Sea Storm 113, 52°03'07"N, 177°23'55"E, 128 m, 10 Jul 2002, 1 male, USNM 1123007; Sea Storm 115, 52°04'16"N, 177°19'04"E, 165 m, 10 Jul 2002, 1 indet. in alcohol, USNM 1123020; Sea Storm 116, 52°04'10"N, 177°14'25"E, 87–94 m, 11 Jul 2002, 1 female, USNM 1123006; Sea Storm 118, 52°00'14"N, 177°49'40"E, 104–111 m, 11 Jul 2002, 1 female, USNM 1123283; Sea Storm 122, 52°02'49"N, 179°25'18"E, 143 m, 13 Jul 2002, 6 male colonies, some in alcohol, and SEM stub 1499, USNM 1123043–44, 1123046, 1123048–49; Sea Storm 124, 52°16'24"N, 179°55'47"E, 88 m, 13 Jul 2002, 1 male in alcohol; Sea Storm 129, 51°53'24"N, 179°44'07"E, 84–93 m, 14 Jul 2002, 1 male, USNM 1123032; Sea Storm 130, 52°12'10"N, 176°12'40"E, 86 m, 15 Jul 2002, 1 female, USNM 1123002; Sea Storm 146, 52°15'55"N, 174°48'02"W, 113 m, 20 Jul 2002, 1 male in alcohol, USNM 1123019; Shishaldin, 51°53.84'N, 177°44.88'W, 374 m, Feb 2000, 1 male, USNM 1122495; Shishaldin, 52°27'14"N, 179°30'54"E, 218 m, 2 Feb 2000, 1 female, USNM 1122521; Vesteraalen 3, 52°38'12"N, 169°46'35"W, 75 m, 21 May 2000, 1 female, USNM 1123373; Vesteraalen 5, 54°40'43"N, 169°06'11"W, 102 m, 21 May 2000, 1 female, 1 male, USNM 1123372; Vesteraalen 8, 53°09'28"N, 167°04'14"W, 154 m, 22 May 2000, 1 male in alcohol, USNM 1123371; Vesteraalen 941–36, 52°56'N, 169°31'W, 0–227 m, 10 Jun 1994, 1 male, USNM 96261; Vesteraalen 941–151, 52°10'N, 179°44'E (topotypic), 0–90 m, 10 Jun 1994, 1 female, USNM 96267; Vesteraalen 941–153, 52°10'N, 179°43'E (topotypic), 0–94 m, 10 Jun 1994, 2 female, USNM 96268; Vesteraalen 941–167, 51°54'N, 178°20'E, 0–150 m, 19 Jul 1994, 3 male, SEM stub 1498, USNM 96264; Vesteraalen 941–185, 52°03'N, 176°31'E, 0–91 m, 24 Jul 1994, 1 female, USNM 96263; Vesteraalen 941–210, 53°07'N, 170°56'E, 0–92 m, 30 Jul 1994, 2 males, USNM 96266; University of Washington, 51°32'N, 179°15'W, 278–289 m, 1 Sep 1968, 1 female, USNM 96250; McClusky, coll., 51°53'14"N, 179°47'50"E, 351–393 m, 30 Mar 2000, 1 female, USNM 1122448; off Sharma, AK, depth unknown, 2 female, USNM 76539;

Colonies variable in shape, ranging from planar (Fig. 11G) to multi-planar to bushy (Fig. 11A, E), the growth form possibly moderated by commensals (see Remarks). Branch tips usually blunt and circular to slightly flattened in cross section, 2.5–3.0 mm in diameter, more slender if affected by commensals; branch anastomosis not uncommon. Largest colony (USNM 96523) 28 cm in height; colonies attached by massive, dense basal branches up to 4.2 cm in diameter (USNM 96262). Coenosteum reticulate-granular in texture, coenosteal strips 50–60 µm wide, separated by thin slits about 10 µm wide; granules rounded, 7–8 µm in diameter. All colonies infested with spionid polychaetes (Polydora) and their characteristic binary axial tubes (see Remarks). Coenosteum pale orange.

Cyclosystems circular, 0.9–1.1 mm in diameter, and slightly (about 1 mm) raised above coenosteum; cyclosystems uniformly arranged on three or all four sides of a branch, rarely in a linear fashion. Gastropores 0.35–0.40 mm in diameter. Gastropore tubes cylindrical, curved (Fig. 13J), and long (often 2–3 times length of gastrostyle), the length and curvature of tube making it difficult to see gastrostyle tip when viewed from above. Ring palisade absent or diffuse, the elements about 50 µm in height and diameter. Gastrostyles lanceolate and up to 0.7 mm in height, bearing long spines up to 70 µm in length.

Dactylotomes 80-110 µm in width; dactylostyles poorly developed, the cylindrical elements about 20 µm in height and 8 µm in diameter. Range of dactylopores per cyclosystem 6–13 (n = 50, average = 9.22 (σ = 1.43), and mode = 10). Supernumerary dactylopores quite common on coenosteum (Fig. 13A–C) and even on pseudosepta, presenting as small (0.09-0.11 mm in diameter), circular, slightly raised (rimmed) pores. Pseudosepta variable in width (Fig. 13D), in the same cyclosystem varying between 0.11 and 0.30 mm; adcauline diastemas also frequently present, each about twice pseudoseptal width.

Female ampullae (Fig. 13J) superficial hemispheres 0.8-1.1 mm in diameter; efferent pores rarely expressed, but if present, occurring in lateral position and somewhat recessed into coenosteum, each about 0.25 mm in diameter. Male ampullae (Fig. 13K) primarily internal, visible on coenosteal surface only as low mounds 0.3-0.5 mm in diameter, often with a small (30 µm diameter) apical efferent pore. Male ampullae often occur in high density clusters, directly adjacent to one another.

Virtually every colony of Stylaster brochi examined contained commensal spionid polychaetes of the genus Polydora (K. Fauchald, per. comm.) , such that this character was informally used to distinguish it from other Stylaster species, such as Stylaster campylecus. Almost every branch is bored axially by this robust worm, which forms binary longitudinal tubes 0.7-0.8 mm in diameter that are figure 8-shaped in cross section (Fig. 15K). Several worms may occur in the same colony, each having one or more efferent openings somewhere on the colony surface. It is easy to conjecture an advantage to the worm in this relationship, i.e. a secure place to live and protection from predators, but it is difficult to imagine an advantage to the stylasterid, as the worm must weaken the strength of the branches as well as compete for the same filtered plankton in the water. Thus, it would seem that these polychaetes are parasites on the coral. Large colonies of Stylaster brochi also form substantial three dimensional habitats for a variety of invertebrates, including sponges, bryozoans, hydroids, barnacles, bivalves, and ophiuroids. Heavy encrustation by sponges seems to promote a more delicate colony growth form, in which the terminal branches are only 1.5 mm in diameter (Fig. 11E). In a monograph otherwise devoted to stylasterids from Sagami Bay, Japan, Eguchi (1968) inexplicably described Allopora abei from “the Aleutian Islands.” Although the type was not examined, and Cairns (1983b) suggested a synonymy with Stylaster polyorchis Fisher, 1938, the illustrations provided by Eguchi suggest a synonymy with Stylaster brochi.Of 86 colonies examined, 35 are female, 40 male, and 11 indeterminate, resulting in a fairly equal sex ratio.Stylaster brochi is one of the most common and one of the largest growing stylasterids in the Aleutian Islands. It can be distinguished from other Alaskan species in Stylaster (Group A) by its usually planar growth mode, higher number of dactylopores per cyclosystem, and variable width of its pseudosepta (see Table 2 for additional comparisons).

Widespread throughout Aleutian Islands from west of Attu Island to Unalaska (including Petrel Bank), with one disjunct record near Sharma (near Anchorage); 75–351 m, but most records between 100–200 m.

Holotype, 1 female colony, and SEM stub 1500, dry, USNM 43271 (Fig. 11C). Type locality. Albatross 4777: 52°11'N, 179°49'E (Petrel Bank, Aleutian Islands), 79–95 m.

Holotype.

The holotype (Fig. 11C) is a small, arborescent colony 6 cm in height and 7 cm in width, with a basal branch diameter of 9.3 mm. Branches cylindrical and blunt tipped, the tips measuring 3-5 mm in diameter. Coenosteum reticulate-granular in texture, coenosteal strips 50-55 µm wide, separated by slits 13-15 µm wide. Coenosteum also covered with small papillae (nematopores). Binary spionid worm tubes present along branch axes. Coenosteum light orange to pink.

Cyclosystems on all sides of branches, circular, 1.0–1.2 mm in diameter. Gastropores circular, 0.35–0.45 mm in diameter. Gastropore tube cylindrical and usually slightly curved such that gastrostyle tip is not visible from apical view; ring palisade absent. Gastrostyle lanceolate.

Cyclosystems flush to only slightly raised above coenosteum; surface of pseudosepta porous. Dactylotome width 0.08-0.11 m. Range of dactylopores per cyclosystems 5-11 (n = 50, average = 6.46 (σ = 1.03), and mode = 6). Small (0.11–0.14 mm diameter), circular supernumerary dactylopores fairly common (Fig. 14A-C). Dactylostyles rudimentary (Fig. 14H).

Female ampullae (Fig. 14A, I–J) superficial hemispheres up to 1.1 mm in diameter, often bearing low ridges radiating from their apex. Male ampullae unknown.

Although only one specimen is known of this species, it does appear to be distinctive. Perhaps most similar to Stylaster brochi, it differs from that species in having flush cyclosystems, fewer dactylopores per cyclosystem, and ridged female ampullae (Table 2).

Known only from one specimen from the type locality.

Allopora verrillii: 5 badly worn, dry, female syntypes, the largest 44 mm in diameter (USNM 4193, Fig. 11H). All branches are eroded from the colony, thus resembling an encrusting colony. Collected together with four dry topotypic specimens (USNM 8850).

Chika Island, Akutan Pass, near Unalaska, Aleutian Islands, on beach.

Allopora moseleyi: Holotype, 1 small (18 mm) dry colony, USNM 6851 (Fig. 11F).

Kiska Harbor, Kiska Island, Aleutian Islands, on beach.

Types of the two species; Alb-4777, 52°11'N, 179°49'E, 95 m, 5 June 1906, 1 female, 1 male, 1 indet., and SEM stub 1501, USNM 53394 and 76524 (mentioned by Fisher 1938); unnumbered Albatross station, Sucia Islands, near San Juan Island, Washington, 16 Sep 1890, 2 female, 11 male colonies, and SEM stub 1513, USNM 76526–28 (mentioned by Fisher 1938); Delta 5622, 51°57'36.54"N, 176°49'58.32"W, 140 m, 24 Jul 2002, 1 male, and SEM stub 1503, USNM 1123299; Delta 5625, 51°57'42"N, 176°50'01"W, 155 m, 25 Jul 2002, 1 male, USNM 1027819; Patricia Lee, 51°53.44'N, 179°47.7'E, 298 m, 1 indet., AB00–41b; Sea Storm 122, 52°02'49"N, 179°25'18"E, 143 m, 13 Jul 2002, 2 female colonies in alcohol, USNM 1123058 (attached to Distichopora borealis, USNM 1123061); Sea Storm 123, 52°10'53"N, 179°37'02"E, 124 m, 13 Jul 2002, 3 female, 2 male, 1 indet., USNM 1123053, 1123056; Sea Storm 129, 51°52'24"N, 179°44'07"E, 84–93 m, 14 Jul 2002, 1 male in alcohol, USNM 1123051; Sea Storm 155, 52°38'43"N, 172°27'27"W, 393 m, 22 Jul 2002, 1 female, USNM 1122763; Vesteraalen 941–40, 52°53'N, 169°59'W, 0–62 m, 11 Jun 1994, 1 female, USNM 96260; Vesteraalen 941–151, 52°10'36"N, 179°43.7'E, 87–92 m, 10 Jul 1994, 1 male, and SEM stub 1502, USNM 1123537; south of Semisopochnoi Islands, 366 m, 1 indet., USNM 88368; Ralston Island, near Juneau, depth unknown, 1 indet., AB04–21; Stubbs Island, BC, depth unknown, 2 indet., AB02–02; Wooden Island, AK, depth unknown, 2002, 1 dry, AB02–150b; Middle Cross Sound, AK, 15–21 m, 27 Jul 1978, 1 indet., AB78–120a; North Pass, Lincoln Island, AK, depth unknown, 2 indet. in alcohol, AB05–37.

Colonies arborescent, dichotomously branching to form a three dimensional bush; branch tips blunt to slightly clavate, 3.0–4.5 mm in diameter. Largest colony (USNM 1027819, Fig. 11B) 3.5 cm tall, 7.0 cm wide, and attached by a basal branch 11 mm in diameter. Colonies usually attached to stones or bivalve shells. Coenosteum reticulate-granular in texture, coenosteal strips 52–55 µm wide, separated by thin slits 10–13 µm wide. Strips covered with small (8–10 µm in diameter) spines, occurring 4–5 across width of a strip, conferring a fine, granular or “sugary" texture. Coenosteal papillae common. Most colonies infested with spionid worms and their characteristic binary tubes (Fig. 15A, K). Coenosteum light orange.

Cyclosystems occur on all sides of branches, circular, and 1.0–1.2 mm in diameter. Gastropore circular and small (0.25–0.30 mm in diameter). Gastropore tubes funnel-shaped near surface but cylindrical adjacent to gastrostyle, straight, and often quite long in thick branches. Ring palisade robust near gastrostyle tip, composed of squat, clavate elements about 40 µm in diameter. Gastrostyles lanceolate to elongate (up to 1.5 mm, Fig. 15H), with a pointed tip; gastrostyles covered with anastomosing, longitudinal, spiny ridges, the spines quite long (up to 65 µm in length) and sharp.

Cyclosystems flush to only slightly raised above coenosteum. Dactylotomes 0.07–0.10 mm in width, sometimes becoming obsolete within a system by infilling of the axial slit, resulting in just an apical pore. Dactylostyles robust (Fig. 15F, M), composed of tall slender cylindrical elements up to 60 µm in height and 10–15 µm in diameter. Range of dactylopores per cyclosystem 5–10 (n = 50, average = 7.10 (σ=1.16), and mode = 7). Pseudosepta triangular; diastemas rare.

Female ampullae primarily internal (Fig. 15K), with only a slight superficial swelling; internal diameter of ampullae 0.7–0.8 mm. Efferent pores of female ampullae never observed. Male ampullae (Fig. 15H, L) also primarily internal, visible on surface only as small dimples about 0.4 mm in diameter; internal cavity diameter 0.3–0.5 mm.

Stylaster verrillii is similar to Stylaster venustus (Figs 16A–I, 17F–G), but differs in having orange, bushy coralla (not pink to purple planar colonies, Fig. 17G); larger cyclosystems (1.0–1.2 mm vs 0.7–0.9 mm in diameter); larger diameter and blunt distal branches; triangular (not rectangular, Fig. 16B) pseudosepta; and straight-sided gastropore tubes (not hemispherical, Fig. 16B)(also see Table 2). Both species are confined to relatively shallow water and have overlapping distributions off British Columbia and Washington. According to the ICZN (1999) article 31.1.3, the original spelling verrillii should be preserved in preference to verrilli.

Known from Kiska Harbor, Aleutian Islands to Sucia Islands, Washington; 21-393 m, although most records between 60-155 m.

Holotype: 1 large dry male colony, and SEM stub 1504, USNM 1122740 (Fig. 27A-B). Paratypes: 52°21.20'N, 171°02.77'W, 475 m, 1 Sep 2000, 1 dry female colony, and SEM stub 1505, USNM 1122739; Amukta Pass, depth unknown, 1996, 2 dry male colonies, USNM 1122741. Type locality. 52°17.86'N, 170°58.28'W (southeast of Amukta Island), 375 m, 12 Sep 2000.

The specific name repandus (from the Latin, meaning “bent backwards”, “undulate”) refers to the complexly folded coenosteal lamellae of this species.

Types.

Colonies firmly attached to a hard substrate by a robust basal stem and encrusting base, the base being 9 cm in diameter and the basal stem 5 cm in diameter in the case of the holotype. Immediately above basal stem the colony divides into two or three lamellae (Fig. 27C), each lamella (or sheet) of coenosteum increasing its surface area by folding its surfaces into a complex three-dimensional structure similar to that of Cyclohelia. Short (up to 15 mm) cylindrical branches project from plane of colony, but always in response to housing a parasitic spionid worm tube. Holotype (Fig. 27A–B) 23 cm tall and 19 cm in width. Coenosteal lamellae thin at edge, only 2.0–2.5 mm thick, and thus easily damaged during collection; basal lamellae up to 10 mm in thickness. All colonies examined heavily infested with spionid worm tubes. Coenosteum reticulate-granular in texture, the strips being about 30 µm wide, bordered by slits about 9–19 µm thick; granules spinose. Coenosteum covered uniformly with small papillae (Fig. 28B). Coenosteum light orange, but central core a light shade of pink.

Cyclosystems equally common on both faces of lamellae, and even occur on lamellar edges, often arranged in transverse rows of up to 15 cyclosystems that parallel lamellar edge; diameter of cyclosystems 1.0–1.15 mm. Gastropore tube funnel-shaped near branch surface, and straight but constricted, the upper diameter being about 0.34 mm in diameter, the constriction corresponding to a diffuse ring palisade, the blunt elements being up to 60 µm tall and 40 µm in diameter. Gastrostyles lanceolate, pointed, and bear longitudinal, spinose ridges. Illustrated style (Fig. 28D) 0.53 mm in height and 0.26 mm in basal diameter.

Cyclosystems almost flush with coenosteum, the dactylopore slits raised only slightly above coenosteum; dactylotomes 0.15-0.17 mm in width. Based on 74 cyclosystems the range of dactylopores per cyclosystem is 1-11 (average = 3.94 (σ = 2.05), and mode = 4). In many cyclosystems there is an adcauline diastema (Fig. 28E), often produced by the infilling of 1–3 adcauline dactylopores, these dactylopores becoming obsolete. Dactylostyles robust, composed of an almost unilinear arrangement of cylindrical, blunt to clavate elements up to 60 µm tall and 13–15 µm in diameter (Fig. 28D, H, J–K).

Female ampullae (Fig. 28L–M) low swellings on coenosteum 0.9–1.1 mm in diameter (internal diameter 0.7–0.8 mm), each with a peripheral efferent pore 0.3–0.4 mm in diameter that faces upward. Male ampullae (Fig. 28I) densely arranged, superficially visible only as inconspicuous mounds 0.5–0.6 mm in diameter (internal diameter 0.4–0.5 mm), often with an irregularly shaped apical efferent pore about 60 µm in diameter.

Among the 80 Recent species in the genus Stylaster (Appeltans et al. 2011: www.marinespecies.org), Stylaster repandus is the only one to have a lamellate growth form. It is very similar in growth form to Cyclohelia lamellata and Errinopora undulata, and is one of five stylasterid species to have lamellate colonies (see Discussion of Errinopora undulata).

Known only from three localities in the vicinity of Amukta Island, Aleutian Islands; 375–475 m.

Allopora campyleca: Holotype: Alb-3480, 1 dry male colony, now in two pieces, length 16 cm, and SEM stub 1524–25, 1545, USNM 42870 (Fig. 17A). Paratypes: Alb-3480, 7 dry colonies and 7 in alcohol, and SEM stub 1526, USNM 43767, 52262, 52265, 58099, and CAS 28297; Alb-2852 (missing in 2011); Alb-2858, 3 dry colonies (not considered conspecific with Stylaster campyleca); Alb-3599, 2 dry colonies (1 male is Stylaster campylecus, 1 female is Stylaster brochi), USNM 76814; Alb-4230, 1 dry male colony (not considered to be conspecific with campyleca); Alb-4302, 2 female dry colonies, USNM 76816. Type locality. Alb-3480: 52°06'N, 171°45'W (Amukta Pass, Aleutian Islands), 518 m.

Allopora polyorchis: Holotype: Alb-3480, 1 large dry colony now in two pieces, and SEM stubs 1527–28, USNM 43266 (Fig. 17B). Paratypes: Alb-3480: about 15 dry branch fragments, USNM 76540–76542, CAS 28293. Type locality. Alb-3480: 52°06'N, 171°45'W (Amukta Pass, Aleutian Islands), 518 m.

Allopora campyleca tylota: Syntypes: Alb-4781, 4 dry female colonies, the largest 15 cm in height, and SEM stub 1539, USNM 43263, and 12 dry male branches, and SEM stub 1540, USNM 86000 (Fig. 17C). Type locality. Alb-4781: 52°14'30"N, 174°13'E (off Agattu I., Near Islands, Aleutians), 882 m.

Allopora moseleyana: Holotype: Alb-4781: 1 dry male colony now in two pieces, largest 13 cm in length, USNM 42869 (Fig. 17D). Paratypes: Alb-4781, 1 dry male colony, USNM 86003; Alb-3480, 3 female and 1 male dry colonies, and SEM stub 1519, USNM 76556, 76557; Alb-3480, 2 dry female and 1 male colonies (considered as Stylaster leptostylus), USNM 76555. Type locality. Alb-4781: 52°14'30"N, 174°13'E (off Agattu I., Near Islands, Aleutians), 882 m.

Types of Allopora campyleca, Allopora polyorchis, Allopora campyleca tylota, and Allopora moseleyana; Alb-3480, numerous branch fragments (topotypic), USNM 76565; Alaskan Leader-35, 53°01'42"N, 170°05'59"W, 200–400 m, 4 Jun 2000, 1 female, USNM 1122510; Alaskan Leader 64, 53°07'N, 166°53'42"W, 324–766 m, 21 Jun 2002, 1 female, USNM 1122484; Alb-4781, type locality, 1 female, USNM 76700; Ballyhoo, 54°47'20"N, 178°46'53"E, 254 m, 5 Jun 2000, 1 female, USNM 1122535; Ballyhoo, 54°42.44'N, 178°46.83'E, 250 m, 5 Jun 2000, 1 female, AB00–0013; Delta, 51°50'55"N, 179°49'26"W, 125 m, 17 Jul 2002, 1 indet., USNM 1123463; Delta Alfa, western Aleutian Islands, depth unknown, 1961, 1 female, USNM 52447; Dominator 971–181, 51°27'43"N, 176°38'20"E, 384 m, 27 Jul 1997, 2 female, 2 male, USNM 1123363; Jason 2095–7-7, 51°48.693'N, 173°49.965'W, 843 m, 25 Jul 2004, 1 male, AB09–0013; Jason 2102–7-8, 51°30.56'N, 177°55.36'W, 824 m, 2 Aug 2004, 6 male, AB09–0012; Jason 2101–9-1, 51°31.43'N, 177°57.5'W, 494 m, 2 Aug 2004, 1 male, AB09–0015; Jason 2103–15–1, 51°50.968'N, 179°51.007'E, 678 m, 1 male, AB08–0037; Jason 2104–1-5, 51°43.83'N, 179°36.0'W, 1011 m, 5 Aug 2004, 1 female, 1 male, AB08–0038 and AB09–0016; MF 833–38, 51°42'54"N, 178°51'30"W, 582 m, 3 Aug 1983, 1 male in alcohol, USNM 77055; MF 833–47, 51°55'36"N, 176°52'48"W, depth unknown, 5 Aug 1983, 1 female, USNM 96529; North Pacific, 52°04'22"N, 176°58'01"E, 384 m, 20 Oct 2000, 1 male, USNM 1122539; Ocean Olympic, 52°09'06"N, 176°09'48"E, 384 m, 2000, 1 male, USNM 1122536; Pacific Knight 941–49, 52°46'N, 171°45'W, 0–340 m, 14 Jun 1994, 1 female, USNM 96528; Pacific Knight 941–75, 52°31'N, 173°30'W, 0–213 m, 20 Jun 1994, 1 male, USNM 96527; Pacific Knight 941–204, 53°06'N, 171°42'E, 0–455 m, 31 Jul 1994, 1 female, 1 male, USNM 96249 and 1123534; Patricia Lee, 52°21'09"N, 179°32'52"E, 375 m, 2000, 1 female, USNM 1122500; Sea Storm 90, 51°36'30"N, 177°10'48"W, 202–217 m, 4 Jul 2002, 1 male in alcohol, USNM 1123012; Sea Storm 91, 51°40'51"N, 177°10'49"W, 82 m, 4 Jul 2002, 1 male, USNM 1123284; Sea Storm 92, 51°33'34"N, 177°36'59"W, 367 m, 4 Jul 2002, 1 female in alcohol, 1 male, USNM 1123028–29; Sea Storm 107, 52°10'28"N, 175°14'14"E, 214 m, 8 Jul 2002, 1 female, 2 male in alcohol, USNM 1123001, -05, -31; Sea Storm 108, 52°11'32"N, 175°17'E, 208 m, 8 Jul 2002, 1 female, 1 male, both in alcohol, USNM 1122998 and 1123041; Sea Storm 109, 52°17'16"N, 175°20'56"E, 238 m, 8 Jul 2002, 2 indet. in alcohol, USNM 1122997 and 1123536; Sea Storm 111, 52°16'20"N, 175°59'13"E, 137 m, 9 Jul 2002, 1 male, 1123034; Sea Storm 112, 52°15'12"N, 176°00'42"E, 137 m, 9 Jul 2002, 1 indet., USNM 1122999; Sea Storm 134, 52°14'38"N, 176°01'25"E, 138 m, 15 Jul 2002, 1 indet. in alcohol, USNM 1123033; Sea Storm 138, 52°13'50"N, 175°14'31"E, 146 m, 16 Jul 2002, 1 female, 1 male, USNM 1122769 and 1122965; Sea Storm 148, 52°28'16"N, 173°19'10"W, 194 m, 21 Jul 2002, 2 male, USNM 1122748 and 1122752; Sea Storm 150, 52°30'47"N, 173°29'W, 213 m, 21 Jul 2002, 1 female, USNM 1122758; Sea Storm 151, 52°33'40"N, 173°19'10"W, 203 m, 21 Jul 2002, 1 female, 1 male, USNM 1122755–6; Sea Storm 155, 52°38'43"N, 172°16'23"W, 393–401 m, 22 Jul 2002, 2 indet., USNM 1122761, -64; Shishaldin, 54°07'N, 179°45'E, 366 m, 20 Feb 2000, 1 female, USNM 1122529; Shishaldin, 54°24'03"N, 179°36'11"E, 313 m, 25 Feb 2000, 1 female, USNM 1122532; Shishaldin, 53°56'54"N, 179°49'31"E, 318 m, 14 mar 2000, 1 indet., USNM 1122568; Chew, coll., 51°32'N, 179°15'E, 218–289 m, 1 Sep 1968, 3 female, USNM 76573 and 96532; Haaga, coll. 53, 51°24;12:N, 177°37'20"W, 12 Jun 2000, 1 female, USNM 1122515; Haaga, coll., 54, 51°45;48"N, 178°09'47"W, 441–791 m, 10 Jun 2000, 1 female, 1 male, USNM 1122496 and AB02–30; McCloskey, coll., 52°03'26"N, 179°12'20"E, 475 m, 27 Apr 2000, 2 indet., USNM 1122449 and 1122461; McCloskey, coll., 52°17'45"N, 179°28'57"E, 28 May 2000, 1 female, USNM 1122964; McCloskey, coll., 51°16'46"N, 178°56'01"E, 373 m 21 May 2000, 2 indet., USNM 1122463; Miller, coll., 51°31'09"N, 176°53'14"W, 375 m, 2000, 1 female, USNM 1122498; Myer, coll., 52°15'N, 173°30'W, 208–274 m, 20 Nov 1973, 4 female, USNM 76567; Slear, coll., 52°07'54"N, 177°14'46"E, 238 m, 8 Dec 2000, 1 female, USNM 1122453; Slear, coll., 51°54'04"N, 179°17'28"E, 567 m, 9 Dec 2000, 2 female, USNM 1122450, -51; Stone, coll., 51°51.133'N, 179°50.9'E, 630 m, 8 Aug 2005, 1 female, AB05–0055; Tierny, coll., Cross Sound, Alexander Archipelago, 334 m, 30 Jul 1953, 1 indet., USNM 76569;

Corallum essentially uniplanar or multiplanar, with occasional short side branches oriented perpendicular to flabellum. Branches anastomose only in larger colonies, the largest colony being the holotype of Stylaster polyorchis, which is 28 cm tall and 35 cm broad, having a massive, dense basal branch diameter of 3.9 cm (Fig. 17B). Distal branches circular to slightly flattened in cross section; larger-diameter branches often rectangular in cross section, the longer axis of the rectangle oriented perpendicular to plane of flabellum. Commensal spionid worm tubes not present. Coenosteum reticular-granular in texture, the coenosteal strips 50–55 µm in width, the slits being a discontinuous series of elongate pores about 15 µm in width; strips covered by small granules. Although generally reticulate in texture, coenosteal strips parallel and straight on exsert abaxial side of each cyclosystem (Fig. 18A). In some specimens the coenosteum is porcellaneous (polyorchis form, Fig. 18I), whereas in others (typical form, Fig. 18G–H) it appears to be more porous. Coenosteum white, pale orange, and pale pink.

Cyclosystems linearly arranged on both edges of branches, as well as on anterior face, and occasionally on posterior face. Those on branch edges often closely spaced, sometimes directly adjacent to one another (Fig. 18C) or even coalescent. Cyclosystems circular, elliptical, or irregular in shape, 1.0–1.3 mm in diameter, slightly flared, and standing slightly exsert from branch; gastropores circular, 0.40–0.45 mm in diameter. Gastropore tubes cylindrical and usually slightly curved (Fig. 18M) on distal branches, such that gastrostyle tip is difficult to see; ring palisade often absent or only poorly developed. Gastrostyles lanceolate, about 0.5 mm in height, and occupying only lower quarter of gastropore tube; H:D about 2.3–2.5. Gastrostyle bears spines up to 0.4 mm in length.

Dactylotomes 0.10–0.11 mm in width; dactylostyles inconspicuous. Range of dactylopores per cyclosystem is 7–17 (n = 50, average = 11.94 (σ = 2.4), mode = 10). Supernumerary dactylopores absent. Pseudosepta slender and fairly uniform in width, 0. 11–0.13 mm in width, an adcauline diastema of about twice pseudoseptal width sometimes present.

Female ampullae (Fig. 18L) large, smooth, superficial hemispheres 1.0–1.1 mm in diameter, often having a lateral efferent pore about 0.25 mm in diameter. Male ampullae (Fig. 18A–B) superficial swellings 0.4–0.5 mm in diameter, often clustered on anterior face.

Fisher (1938: 505) discussed the similarities of Stylaster campylecus and Stylaster polyorchis, but concluded they were different species based on six minor differences: Stylaster polyorchis had smaller cyclosystems, straighter gastropore tubes, no ridges on the inside of the gastropore tube, often linked cyclosystems, a ring palisade, and wrinkled female ampullae. Based on more detailed SEM observations on many more specimens, these differences are considered to be intraspecific variation, the holotype of Stylaster campylecus itself having some linked cyclosystems and wrinkled female ampullae. The ring palisade is absent in most coralla, but in some specimens is weakly developed. Stylaster campylecus tylotus was also compared to but differentiated from typical Stylaster campylecus by Fisher (1938) in having a more delicate corallum, a larger ring palisade, a stouter gastrostyle, larger male ampullae, and more dactylopores per cyclosystem, but closer examinations also shows all these character to be within the range of variation of typical Stylaster campylecus (see Table 2). Likewise, no significant differences could be found between Stylaster moseleyanus and Stylaster campylecus, and thus these four taxa are considered to be the same. Interestingly, types of three of the four taxa were collected at Albatross station 3480, prompting Fisher (1938: 514) to remark about “the extraordinary number of species and subspecies dredged at station 3480, ” considering the possibility that hybridism might be taking place.Stylaster campylecus and Stylaster brochi are the two most commonly collected stylasterids in the Aleutian Islands. Stylaster campylecus can be distinguished from other Alaskan species in Stylaster (Group B) by its slightly flared cyclosystems and the linearity of the coenosteal strips near the cyclosystems (Table 2). The corallum was found to be 100% aragonitic according to Cairns and Macintrye (1992). Of 94 colonies examined, 44 are female, 39 male, and 11 indeterminate, resulting in a fairly equal sex ratio.

Known from throughout the Aleutian Islands from Agattu Island to Unalaska, including Petrel and Bowers Banks, two disjunct records in Alexander Archipelago; 82-1011 m, but most records from 150-500 m.

Holotype: Alb-3480, 1 dry male colony 8.5 cm in height, and SEM stub 1544, USNM 43270 (Fig. 17E). Paratypes: Alb-3480, 4 female, 2 male colonies, dry, and SEM stub 1536–38, USNM 76817. Type locality. Alb-3480: 52°06'00"N, 171°45'00"W (off Seguam Island, Amukta Pass), 518 m.

Types. Alb-3480, 2 female, 1 male colonies, dry, USNM 76555 (paratype of Allopora moseleyana).

Corallum uniplanar, branching equal and dichotomous; no anastomosis of branches. Largest colony (the holotype, Fig. 17E) 8.5 cm in height and 7.0 cm in width, with a basal branch diameter of 8.4 mm. All branches circular in cross section. Commensal spionid polychaetes absent. Coenosteum reticulate-granular in texture, the coenosteal strips 45–55 µm in width, the slits about 15 µm in width; strips; strips not linear near cyclosystems. Coenosteum white.

Cyclosystems occur on branch edges and anterior face, but rarely on posterior face, those on edges not aligned in rows. Cyclosystems circular, 1.0–1.1 mm in diameter, and raised only slightly above branch coenosteum. Gastropores about 0.35 mm in diameter, leading to a slightly curved, funnel-shaped upper tube that narrows to a cylindrical lower part that houses the gastrostyle (Fig. 19G–H); ring palisade absent. Gastrostyles elongate-lanceolate, up to 0.6 mm in length, occupying lower half of gastropore tube, its pointed tip easily seen in an intact cyclosystem; H:D about 3.5.

Dactylotomes 0.10-0.13 mm wide; dactylostyles moderate in size, elements up to 50 µm in length. Range of dactylopores per cyclosystem 7–12 (n = 50, average = 9.76 (σ = 1.92), mode = 9). Supernumerary dactylopores absent. Pseudosepta slender and fairly uniform in width (0.10–0.11 mm), an adcauline diastema of twice that width sometimes present.

Female ampullae (Fig. 19D) large, smooth, superficial hemispheres 0.9-1.1 mm in diameter, occasionally having a lateral efferent pore about 0.20 mm in diameter. Male ampullae (Fig. 19A) superficial swellings 0.45-0.55 mm in diameter, often clustered on anterior and posterior branch faces; apical efferent pores about 25 µm in diameter.

Fisher (1938) originally differentiated forma leptostyla from typical Allopora moseleyana (=Stylaster campylecus) based on its more slender gastrostyle and smaller male ampullae. We cannot find a difference in ampulla size between forma leptostyla and typical Stylaster campylecus, but the gastrostyle of leptostyla is longer and more slender than that of Stylaster campylecus, occupying more of the gastropore tube (and thus having a higher H:D ratio) and being more visible from external view. In addition to this difference, forma leptostyla differs from Stylaster campylecus in having equal, non-anastomosing branching; branches circular in cross section; less exsert cyclosystems; non-linearly arranged cyclosystems; fewer dactylopores per cyclosystem; and consistently reticulate coenosteal strips (see Table 2). For these reasons this form is elevated to species rank but is considered to be closely related to Stylaster campylecus.

Known only from type locality.

Holotype: Alb-4784, 1 dry female colony 9 cm in height, and SEM stubs 1516, 1541, USNM 43265 (Fig. 17H). Paratypes: Alb-4784, 2 female, 2 male, 1 indet. colonies, and SEM stub 1517–18, dry, USNM 76811. Type locality. Alb-4784: 52°55'40"N, 173°26'E (off East Cape, Attu Island, Aleutians), 247 m.

Types; Delta 5999–8E-3, 51°21.042'N, 179°30.483'W, 115 m, 4 Jul 2003, 1 male, AB10–0001; Delta 6230–20–18, 52°28.142'N, 173°35.882'W, 190 m, 8 Jul 2004, 5 male branch fragments in alcohol, AB10–0004; Shishaldin, 54°54.09'N, 178°37.27'E, 366 m, 11 Feb 2000, 1 female, 2 male, AB00–45.

Corallum uniplanar, occasionally with short side branches oriented perpendicular to flabellum; branch anastomosis occurs only in large-diameter basal branches. Largest colony (paratype) 12 cm tall and 8 cm wide, with a basal branch diameter of 3 × 1.5 cm. Distal branches circular to slightly flattened in cross section. Commensal spionid worm tubes common. Coenosteum reticulate-granular in texture, the coenosteal strips 70–80 µm wide, the slits discontinuous and about 10-15 µm wide, the small granules producing a rough texture. On exsert cyclosystems, coenosteal strips are parallel and straight. Most coralla bear some short coenosteal ridges, called “spinous outgrowths” by Fisher (1938: 511), these thin ridges aligned with the branch (up to 1 mm long, 1 mm tall, and only 0.1 mm in width) or aligned with some of the pseudosepta on exterior wall of a cyclosystem (Fig. 20G–H). Coenosteum pale pink-orange.

Cyclosystems arranged uniformly on branches, not linearly, but fewer in number on posterior face. Cyclosystems rarely circular in shape, rather elliptical or asymmetrical, the longer axis of the ellipse up to 1.8 mm. Gastropore tubes cylindrical, slightly curved, and quite deep (up to 3 mm); a well-developed ring palisade present near gastrostyle tip, composed of squat elements about 50 µm in height and width. Gastrostyles lanceolate, up to 0.67 mm, having a H:D of about 3.1, and occupying lower quarter of gastropore tube. Because of curvature of the long gastropore tube, the short gastrostyle, and the wide pseudosepta, the gastrostyle tip is rarely seen when viewed from above.

Dactylotomes 0.085–0.10 mm in width, supernumerary dactylopores being quite rare, usually associated with pseudosepta. Dactylostyle inconspicuous (Fig. 20J). Range of dactylopores per cyclosystem 8–18 (n = 50, average = 11.82 (σ = 2.15), and mode = 11). Pseudosepta slender (0.07–0.21 mm wide), adcauline diastemas twice that width sometimes present; surface of pseudosepta quite porous (Fig. 20F).

Female ampullae (Fig. 20D, G, K–L) superficial hemispheres 1.0–1.3 mm in diameter, having a knobby or papillose surface; efferent pores not evident in material at hand. Male ampullae (Fig. 20M) also superficial swellings 0.50–0.55 mm in diameter. Both types of ampullae clustered on anterior and posterior branch faces.

Fisher (1938) described this taxon as a subspecies of Stylaster campylecus, distinguishing it from the nominate subspecies by having spongy pseudosepta (Fig. 20F), decurrent pseudoseptal ridges on the inside of the gastropore tube (Fig. 20C), and spiny coenosteal outgrowths (Fig. 20G–H). Stylaster trachystomus is otherwise similar to typical Stylaster campylecus in gastropore tube and gastrostyle shape and number of dactylopores per cyclosystem, but is also similar to Stylaster brochi in arrangement of cyclosystems and in hosting commensal spionid polychaetes; it also has unique characteristics as mentioned above (see also Table 2). Although few colonies are known of this species, because it does present a unique set of characteristics, it is considered valid and herein elevated to species rank. The corallum was found to be 100% aragonitic according to Cairns and Macintrye (1992).

Aleutian Islands: from off Attu Island and north of Amalia Island (Andreanof Islands), including Bowers Bank; 115–366 m.

Holotype: 1 dry male colony 13 cm in height, plus many tiny branch fragments, and SEM stub 1514, USNM 42871 (Fig. 21A). Paratypes: Alb-4245, 1 female colony, and SEM stub 1515, USNM 76812; near Sitka, Alaska, coll. E. R. Ricketts, 1 female, deposition unknown (not seen); Alaska, deposition unknown (not seen); Yakutat Bay, Alaska, 152 m, specimens reported by Broch (1936), Zoological Museum Copenhagen (not seen). Type locality. Tenakee Springs, near Juneau, Alaska, depth unknown.

Types; Alaskan Leader 21–91A, 59°31'18"N, 144°42'42"W, 401–600 m, 31 Jul 2002, 1 male, USNM 1122485; Lambert, coll., 55°18'N, 129°57'18"W, 23 m, 28 Mar 1976, 1 male in alcohol, USNM 76976; Freege and Worth, coll., 57°48'N, 134°02'W, 30 m, 17 Apr 2000, 4 branches in alcohol, USNM 1122523; “an Indian", coll., Sitka Bay, depth unknown, about 1884, 2 male branches, USNM 4192.

Corallum consisting of overlapping flabella, also with short branchlets oriented perpendicular to flabella, producing what Fisher (1938: 507) calls “subflabellate’ or a “flattened bush.” Branches do not anastomose, are circular to slightly flattened in cross section, and distally are quite delicate. Largest colony (the holotype, Fig. 21A) 13 cm tall and wide, with a basal branch diameter of 3.2 cm. Commensal spionid worm tubes common. Coenosteum reticulate-granular in texture (Fig. 22E–F), the coenosteal strips 60–65 µm in width, the slits only 6-8 µm wide, the strips covered with low rounded granules, altogether presenting a smooth dense aspect. Coenosteum white.

Cyclosystems occur on branch edges and anterior face, but rarely on posterior face. Cyclosystems circular in shape, small (0.9-1.0 mm in diameter, not 0.6 mm as stated by Fisher 1938), and only slightly elevated above coenosteum; gastropores circular and quite narrow (0.25–0.30 mm in diameter, Fig. 22B). Gastropore tubes cylindrical, slightly curved, such that gastrostyle tip rarely seen in view from above; well-developed ring palisade present (Fig. 22C), consisting of elongate elements oriented longitudinally, each about 45 µm in length and 30 µm in width. Gastrostyles lanceolate, up to 0.5 mm in height, and occupying the lower half of third of the gastropore tube; H:D about 2.7.

Dactylotomes 0.09–0.10 mm wide, the inner slit very shallow, resulting in a ring of essentially apical dactylopores surrounding a thick-walled gastropore tube (Fig. 22B). Dactylostyles well developed, the elements up to 35 µm in height and 10–11 µm in diameter (Fig. 22H). Range of dactylopores per cyclosystem 5–11 (n = 50, average = 8.54 (σ = 1.20), mode = 8). Supernumerary dactylopores present but not common. Pseudosepta 0.12–0.13 mm in width; diastemas rare.

Female ampullae (Fig. 22I) superficial hemispheres 0.8-1.0 mm in diameter, the lateral efferent pores being 0.15-0.20 mm in diameter. Male ampullae (Fig. 22A, J) partially submerged in coenosteum (internal) on distal branches, entirely internal on larger-diameter branches, the outer diameter being about 0.5 mm, the internal diameter of internal ampullae about 0.42 mm; male ampullae often clustered on branch faces.

Although Fisher (1938: 508) included this taxon as a subspecies of Stylaster campylecus, considering it to be “the southern shallow-water race of campyleca, ” there are sufficient differences to warrant raising this subspecies to species rank (Table 2). Distinctive features include its bushy delicate colony, extremely small gastropores surrounded by a thick wall, and relatively low number of dactylopores per cyclosystem. Geographically it occurs only off southeastern Alaska in relatively shallow water, not in the Aleutian Islands. Comparisons to the other subspecies are made in the following account.

Bays and inland passages of southeastern Alaska from off Kayak Island to just north of Dixon Entrance (i.e., Prince of Wales Islands and Portland Canal); 23-401 m.

Holotype: FOMC 1162 (209), male colony, dry, and SEM stubs 1389–91, USNM 1122462 (Fig. 22B). Paratypes: Alaskan Leader 21–108, 54°27'N, 133°55'48"W, 215–563 m, 10 Jul 2002, 1 male, USNM 1122483; Alb-4230, 55°N, 131°W, 198–439 m, 7 Jul 1903, 1 male, USNM 76815 (paratype of Allopora campylecus); FOMC 1158 (206), 48°07'546"N, 125°05'46"W, 246 m, 10 Jul 2008, 1 male in alcohol, USNM 1122465; FOMC 1159 (161), 48°07'56"N, 125°05'45"W, depth unknown, 10 Jul 2008, 3 males, USNM 1122472; FOMC (162), 48°07'56"N, 125°05'46"W, depth unknown, 10 Jul 2008, 1 male in alcohol, USNM 1122471; FOMC 1159 (166), 48°07'46"N, 125°05'41"W, 273 m, 10 Jul 2008, 1 male in alcohol, USNM 1122473; FOMC 1159 (169), 48°07'48"N, 125°05'41"W, 264 m, 10 Jul 2008, 1 male in alcohol, USNM 1122467; FOMC 1162 (203 and 205), 48°08'26"N, 125°11'28"W, 265 m, 12 Jul 2008, 2 males in alcohol, USNM 1122464, and -68; Lindner, coll., AL470 (41), Race Rocks, near Sooke Community, Straits of Juan de Fuca, British Columbia, depth unknown, Jul 2002, 1 male, USNM 1096625; Lindner, coll., AL466 (25), off Triangle Island, British Columbia, depth unknown, 1 male in alcohol, USNM 1096628; Ropos 956 (103), 48.15605°N, 124.9973°W, 288 m, 30 May 2006, 1 male, USNM 1117117; Ropos 957 (116), 48°08'42"N, 125°11'26"W, 285 m, 31 May 2006, 1 female in alcohol, SEM stub 1402, USNM 1117112. Type locality. 48°08'31"N, 125°11'01"W (off Cape Flattery, Washington), 273 m.

Named for the region from which it is primarily known: British Columbia.

Types.

Corallum shape and branching similar to that of typical subspecies: bushy or flattened bushy with delicate terminal branches. Holotype 7 cm tall and 7 cm wide, with a basal branch diameter of 10.1 × 8.1 mm; largest corallum (USNM 1096625, Fig. 21B) 8.5 × 8.0 cm, with a massive basal branch diameter of 3 cm. Commensal spionid worm tubes absent. Coenosteum reticulate-granular in texture, the coenosteal strips 50–60 µm wide, bordered by slits about 10 µm wide, the strips originally covered with irregularly-shaped nodules that are subsequently covered with smoother granular coenosteum (Fig. 23E shows the transition). Coenosteum white.

Cyclosystems occur exclusively on edges of distal branches, but also on anterior face of larger-diameter branches. Cyclosystems circular to elliptical in shape, the larger axis ranging from 1.1 to 1.5 mm, the abaxial edge slightly raised above coenosteum; gastropores circular, 0.45–0.50 mm in diameter. Gastropore tubes somewhat inflated in upper half, changing to a narrow cylinder proximally; a well-developed ring palisade present as in the typical subspecies, the narrow pointed gastrostyle tip projecting through the ring palisade constriction into upper chamber (Fig. 23G) and thus easily visible from above. Gastrostyles elongate-lanceolate (Fig. 23D), occupying lower half of gastropore tube, and up to 0.67 mm in length, having a H:D ratio of 3.1–3.7.

Dactylotomes 0.09–0.10 mm in width, the inner slit short but longer than that of typical subspecies. Dactylostyles well developed, the cylindrical elements up to 38 µm in height and about 14 µm in diameter. Range of dactylopores per cyclosystem 6–13 (n = 50, average = 9.38 (σ = 1.43), and mode = 9). Supernumerary dactylopores rare. Pseudosepta 0.17–0.28 mm in width; diastemas uncommon.

Female ampullae (Fig. 23I) smooth superficial hemispheres 0.9–1.0 mm in diameter, with lateral efferent pores about 0.23 mm in diameter. Male ampullae (Fig. 23J) superficial swellings up to 0.5 mm in diameter, with small apical efferent pores. Both types of ampullae clustered on anterior and posterior faces.

Subspecies columbiensis resembles the typical subspecies in many ways, including colony shape and branching, and ring palisade shape, but also differs in a number of small but consistent characteristics (Table 2). Subspecies columbiensis has larger cyclosystems and gastropores, a slightly higher average number of dactylopores per cyclosystem, a more commodious upper gastropore chamber and deeper dactylotome slits, and a more elongate gastrostyle that is easily seen from above. Dixon Entrance appears to be the border between the two subspecies, the typical subspecies occurring to the north and columbiensis occurring to the south of this body of water. Because of the overall similarity of the two taxa, and their consistent minor differences, including their geographic separation, columbiensis is considered as a subspecies or Stylaster parageus. Of 16 colonies examined, 15 are male and one is female.

Entire coast of British Columbia (Canada) from Dixon Entrance to off Cape Flattery, Washington (USA); 246–285 m.

Stylaster gemmascens alaskanus: Holotype, Alb-3480, 1 dry male branch fragment 4.5 cm in length, USNM 43269 (Fig. 21E); 5 (perhaps one broken from the four mentioned by Fisher) dry paratype branches (2 female, 2 male, 1 indet.), and SEM stubs 1511–12, Alb-3480, USNM 86006. Type locality. Alb-3480: 52°06'N, 171°45'W (Amukta Pass, Aleutian Islands), 518 m.