Palmicellaria dofleini Buchner, 1924 by original designation by Harmer (1957: 876) (= Escharoides teres Ortmann, 1890).

Colony erect, rigid, dichotomously or irregularly branching: branches cylindrical, flattened, or plate-like, fan shaped. Zooidal frontal shield uniformly tessellated, with a few areolar pores near margin or offset centrally in secondarily calcified wall. Orifice deeply immersed, without teeth on distal periphery, without lyrula or condyles, slightly concave or straight proximally; oral spines absent. Secondary orifice at colony surface cormidial, formed by contributions of secondary calcification from distal and lateral zooids. Suboral avicularium lies at proximal margin of secondary orifice, directed proximally or laterally, sometimes enlarged and occupying about half of frontal shield; small, conical tooth associated with avicularium projecting into secondary orifice (Fig. 2). Mandible of the suboral avicularium semicircular or spatulate, but never acute. Vicarious and other frontal avicularia absent. Ovicell globose, acleithral, and is produced by the distal zooid (Fig. 3). Both the endooecium and ectooecium are calcified. Endooecium is completely calcified, whereas ectooecium is not completely covering the endooecium (Fig. 3A, B). Immediately after formation, the ectooecium is then partially covered by the secondary calcification that is coming from the distal and neighbour zooids (Fig. 3B). Finally, the secondary calcification covers most of the ectooecium in the old parts of the colony, but a small area of proximal margin remains uncovered (Fig. 3C). Small basal pore chambers present.

Harmer (1957) defined Buchneria as follows: colony erect, not jointed; large spatulate avicularia present; zooids with a “sinuate” or nearly straight proximal margin of the orifice (the term ‘sinuate’ appears to be misapplied to the evenly concave proximal margin in Buchneria sinuata; perhaps Harmer intended the meaning as ‘having a sinus’); small, acute suboral or lateral avicularia on the edge of the secondary orifice; few frontal pores; and a hyperstomial ovicell with an imperforate central tabula. His generic diagnosis, however, largely derives from Buchneria sinuata Harmer, 1957 from Indonesia. This species is similar to the three Buchneria species treated herein in having erect colony form, few frontal or marginal pores, and a deeply immersed primary orifice. However, it differs substantially from them in having large, spatulate frontal avicularia; hyperstomial ovicells with an imperforate central tabula lacking secondary calcification; and a laterally placed, acute oral avicularium (Harmer, 1957: plate LIV, fig. 19). Buchneria sinuata, therefore, has currently been thougth to belong in another genus, perhaps Osthimosia Jullien, 1888 (Gordon, 1984). Gordon (1984) noted several similarities between Osthimosia virgula and nominal Buchneria sinuata (e.g., broad orificial sinus, a lateral-oral avicularium on peristome, and spatulate frontal avicularia), and suggested the two species may be congeneric. Subsequently, Gordon (1989) observed and illustrated Japanese material of Buchneria present in the Natural History Museum London (NHMUK), and elucidated the umbonuloid frontal shield; he concluded Buchneria cannot be grouped together with Osthimosia and other lepraliomorphs. Unfortunately, I have never had a chance to check the type material of Harmer’s Buchneria sinuata, which is not in NHMUK (Mary Spencer Jones, pers. comm. 11 May 2012) and both institutes Zoological Museum Amsterdam (ZMA) and Naturalis Biodiversity Center in Leiden (Elly Beglinger, pers. comm. 19 September 2012). Although I have not checked the type material, I exclude Harmer’s Buchneria sinuata from the description of the genus in this paper based on the significant differences with the type species of the genus; Buchneria sinuata is also different from other Buchneria species in mainly imperforate frontal shield, small colony size, and preference of unstable substrate which is unusual for Buchneria species. The status of Buchneria sinuata is still unclear and should be clarified in future work. With the removal of nominal Buchneria sinuata from Buchneria, the cormidial orifice and the rounded mandible of suboral avicularia may be considered diagnostic characters for Buchneria. Buchner (1924) described large frontal avicularia, but these are enlarged suboral avicularia; therefore, absence of a large frontal avicularium may also be considered diagnostic for Buchneria.

Gordon (1989) regarded Buchneria close to Celleporaria in Lepraliellidae, based on the similarities between the type species of both genera in the umbonuloid and imperforate frontal shield with marginal areolar pores, broad orifice, and suboral avicularium. However, the ovicell of Buchneria is different from that of Lepraliellidae in having broader proximal window and deeper ooecium, and is more similar to that of Palmiskenea Bishop & Hayward, 1989 in Bryocryptellidae with a few small foramina close to the proximal margin. Buchneria also resembles Palmiskenea in the frontal shield having only marginal areolar pores, but differs from the latter in the orifice without condyles and in polymorphic avicularia. Buchneria resembles Marguetta Jullien, 1903 in having only marginal pores, an ovicell with a few small pores, and oval suboral avicularia, but differs from the latter in lacking frontal avicularia on margin of the frontal shield. Buchneria also resembles Porella Gray, 1848 and Porelloides Hayward, 1979 in having only marginal pores, an ovicell without or with a few small pores, and suboral avicularia, but differs from the latter two genera in lacking lyrula and condyles. Although some species of Porella also lack a lyrula, and species of Porelloides normally lack condyles, a small tooth on the distal margin of the suboral avicularium is characteristic of Buchneria. Considering the similarities of ovicell and orifice morphology between Buchneria and the four bryocryptellid genera, Porella, Palmiskenea, Marguetta and Porelloides, I conclude Buchneria is much better placed in Bryocryptellidae rather than Lepraliellidae.

Harmer (1957) suggested that Haswellia auriculata Busk, 1884 be placed in Buchneria, on the basis of orifice morphology and the small lateral avicularia on the edge of the peristome. He also suggested that the species Haswellia auriculata and Myriozoum marionense Busk, 1884 as described by Calvet (in Jullien and Calvet 1903) represent a single species referable to Buchneria, on the basis of very few frontal pores; a large, spatulate frontal avicularium; the form of the peristome with small avicularia; and immersed ovicells (Harmer, 1957). However, Haswellia auriculata is currently regarded as a junior synonym of Galeopsis pentagonus (d’Orbigny, 1842), and the specimen described as Myriozoum marionense in Jullien and Calvet (1903) is also considered as a species of Galeopsis.

Excluding nominal Buchneria sinuata, Buchneria presently contains three species, which I redescribe here.

Lectotype. Branched colony (MZS 36-2), collected by L. Döderlein, 1882, Sagami Bay. Paralectotype. Branched colony (MZS 36-1, 36-3; NSMT Te-738), collected by L. Döderlein, 1882, Sagami Bay. Other material examined. Fragment of colony ZSM 20043001, collected by F. Doflein, 17 October 1904, entrance of Tokyo Bay, 600 m depth; fragment of colony ZSM 20100261 collected by F. Doflein, 1904−1905, Sagami Bay; single small living colony on pebble and several fragments of living colonies (NSMT TeS-3, TeS-2), collected by NSMT from RV Shinyo-maru, 24 October 2003, Okinose, Sagami Bay (34°58.80'N, 139°31.50'E to 34°59.20'N, 139°31.20'E), 900−950 m depth, by dredge; fragments of colonies (NSMT TeS-4), collected by NSMT from research boat Rinkai-maru, 16 March 2001, SW of Hayama, Sagami Bay (35°11.46'N, 139°28.71'E to 35°11.64'N, 139°28.14'E), 432−580 m depth, by dredge; several living and dead colonies (NSMT TeS-5 to TeS-12) on dead Conchocele bisecta (Conrad, 1849) shells, collected by NSMT from RV Tansei-maru, 24 November 2007, ENE of Hatsushima, Sagami Bay (35°03.41'N, 139°12.55'E to 35°02.73'N, 139°13.73'E), 563−756 m depth, by beam trawl; single small dead colony on pebble (NSMT Te-876), collected by Nagai, 24 April 1997, SW of Shionomisaki, Wakayama Prefecture (33°24.91'N, 135°38.69'E to 33°24.95'N, 135°38.12'E), 500 m depth, by dredge.

ZL, 0.595−1.334 (0.978±0.160); ZW, 0.214−0.840 (0.450±0.133); n=65. OrL, 0.131−0.208 (0.171±0.021); OrW, 0.123−0.219 (0.187±0.018); n=32. AvL, 0.078−0.198 (0.110±0.017); AvW, 0.055−0.148 (0.086±0.016); n=82. OvL, 0.205−0.391 (0.311±0.049); OvW, 0.286−0.439 (0.365±0.043); n=29. Additional measurements: large suboral avicularium (LAv) length, 0.619−0.766 (0.682±0.076); LAv width, 0.398−0.453 (0.426±0.027), n=3.

Colony erect, rigid, dichotomously branching, widely spreading, antler-like, terminal branches slender. Basal part of colony composed of both autozooids and kenozooids. Branches cylindrical, 1.39–4.76 mm wide (2.77±0.85 mm; n=25), with zooids opening all around, four or five zooids across in half-view (Fig. 4A, B). Autozooids subrectangular to oval, tapering proximally, cylindrical in younger ends of branches, arranged in quincunx; zooidal borders indistinct. Frontal shield convex, entirely tessellated with minute depressions, with two to six areolar pores offset from margin (Fig. 5A, B). Orifice (Fig. 5C) deeply immersed, elongated semicircular, about as wide as long, slightly concave proximally; lyrula and condyles absent. Oral spines lacking. Secondary orifice cormidial, bounded by contributions of secondary calcification from distal and lateral zooids, with suture lines often evident between the sectors; secondary orifice roughly oval in young zooids, complex in mature zooids, with suboral avicularium offset to one side and a sharp, raised flattened peristomial flange on the other, often with a sinus between the two (Fig. 5D, E). Suboral avicularium lies on peristome periphery; small, circular, with complete pivot; semicircular mandible directed proximolaterally (Fig. 5D, H); orificial side of rostrum with a rounded-triangular tooth or flange (Fig. 5E). Zooids commonly have the small suboral avicularium replaced by a larger (Fig. 6A) or much larger, hypertrophied oval (Fig. 6B) avicularium (Fig. 6A, B), with the latter type sometimes displaced proximally toward the center of the frontal shield (Figs 4C, 6C). Another type of large avicularium occurs rarely at branch bifurcations (Fig. 5F), appearing almost as a crack in the bifurcation; twice as wide as long, 0.181 mm long by 0.373 mm wide (n=1). Interzooidal kenozooids lacking orifice are interspersed with autozooids on branches (Fig. 5A), but are often much more numerous on side of branch facing inward toward the colony axis than on outer side; kenozooids encircle the base of colony (Fig. 4D). Ovicell (Fig. 5B, G, H) globose, recumbent on distal zooid, roughly as wide as long when fully formed; ooecium smooth, proximal margin slightly curved, ectooecium is not completely covering the endooecium, leaving a large central membranous foramina and small proximal membranous window (Fig. 3A, B). Ectooecium is partially covered by tessellated secondary calcification from neighboring zooids with age (Fig. 5H). The proximal margin with the central pseudopore remains uncovered in the old parts of the colony (Fig. 3C).

Sagami Bay, Sagami Sea, Tokyo Bay, and off Kii Peninsula, at depths of 432–950 m. The collecting depth of the specimen (1921.11.7.9.) in NHMUK is 250–330 fathoms, which means 457–603 m; therefore, the depth given in Harmer (1957) is wrong and should be in feet.

Ortmann (1890) first described Buchneria teres (as Escharoides teres) based on Döderlein’s specimens from eastern Sagami Bay; these specimens had not been reexamined until this study. Buchner (1924) subsequently described Buchneria dofleini (as Palmicellaria dofleini) from Doflein’s Sagami Bay specimens. Although Buchner’s type specimen of Buchneria dofleini was lost during WWII, I found other specimens he identified as this species in the Doflein collection at ZSM. In comparing these specimens with Ortmann’s syntypes of Escharoides teres, I found no diagnostic differences between the two; Buchner’s specimens are simply the distal younger part of branches of Escharoides teres. I thus consider Buchneria dofleini as a junior synonym of Escharoides teres, which accordingly becomes the type species of Buchneria. Buchner (1924) reported large frontal avicularia in his species, but these are enlarged suboral avicularia. Although syntypes of Buchneria teres in the Döderlein collection lack the colony base, I found an entirely kenozooidal colony base in complete colonies recently collected from Sagami Bay (Fig. 4D).

Lectotype. MZS 37-2 (NSMT Te-737), branched colony, collected by L. Döderlein, 1882, Sagami Bay. Paralectotype. MZS 37-1, branched colony, collected by L. Döderlein, 1882, Sagami Bay, 370 m depth. Other material examined. NSMT-Bry R256, Emperor Showa Collection, collected 8 February 1967, 5 km SW of Jogashima, Sagami Bay, 250–400 m depth; NSMT-Bry R267, Emperor Showa Collection, collected 18 March 1968, 4 km WSW of Jogashima, Sagami Bay, 200−220 m depth; NSMT TeS-1, coll. 14 May 2004, west of Ōshima, Sagami Sea (34°40.95'N, 139°17.92'E to 34°40.68'N, 139°18.22'E), 220−277 m depth, beam trawl, RV Tansei-maru; colony (NSMT Te-799), collected by H. Kohtsuka from research boat Rinkai-maru, 10 January 2012, SW of Jogashima, Sagami Bay (35°06.101'N, 139°34.284'E to 35°05.684'N, 139°34.061'E), 218–318 m depth; fragments of colonies (NSMT Te-796, Te-797), collected by M. Hirose from research boat Rinkai-maru, 24 February 2012, WSW of Jogashima, Sagami Bay (35°07.301'N, 139°33.365'E to 35°07.327'N, 139°32.978'E), 300–493 m depth.

ZL, 0.767−1.150 (0.948±0.100); ZW, 0.468−1.050 (0.735±0.116); n=32. OrL, 0.152−0.211 (0.177±0.019); OrW, 0.189−0.245 (0.222±0.023); n=14. AvL, 0.106−0.271 (0.171±0.034); AvW, 0.096−0.193 (0.144±0.024); n=28.

Colony erect, rigid, dichotomously branching, widely spreading (Fig. 7A). Branches flattened, multiserial, with zooids opening all around; 2.33−6.34 mm wide (3.34±0.88 mm, n=25), five to nine zooids across (Fig. 7B). Autozooids rhomboidal, arranged in quincunx (Fig. 7B), zooidal borders indistinct. Frontal shield convex, entirely tessellated with minute depressions, with two to four small areolar pores (Fig. 8A, B) offset from margin. Orifice subcircular, about as wide as long, smooth distally, proximal margin without sinus; lyrula and condyles absent (Fig. 8C). No oral spines. Orifice deeply immersed; aperture at colony surface roughly semicircular in outline, without sinus proximally; cormidial, bounded by contributions of frontal calcification from distal and one or two lateral zooids, with suture lines sometimes evident between the sectors (Fig. 8C, D). Suboral avicularium small, proximal to orifice on the peristome periphery; circular, with complete pivot, rostrum slightly elevated, slightly denticulate, semicircular mandible directed proximolaterally (Fig. 8C, D, E); distal tooth of suboral avicularium small, rounded-conical (Fig. 8D). No other avicularia were observed. On both the edges of branches and in older part of colony, interzooidal kenozooids lacking orifice (Fig. 8F) are interspersed with autozooids; kenozooids especially numerous in the basal part of colony. Ooecium imperforate, smooth, completely immersed, not evident from colony surface; proximal margin almost straight or slightly curved, rarely obscuring the distal edge of primary orifice in oviccelate zooids (Fig. 7C).

Eastern part of Sagami Bay, and the Sagami Sea southwest of Jogashima and west of Ōshima, at depths of 200–493 m.

Examination of Ortmann’s (1890) type specimens revealed this species belongs not in Escharoides but in Buchneria, on the basis of the frontal shield with few pores, absence of oral spines, orifice without lyrula, immersed imperforate ooecium, and the suboral avicularia. Buchneria rhomboidalis is characterized by having rhomboidal zooids and flat branches. This species resembles Buchneria teres, but differs in having flat rather than cylindrical branches, in lacking a peristomial labium and sinus, and in lacking a large avicularium at branch bifurcations. The depth distribution of Buchneria rhomboidalis (200–493 m) is shallower than that of Buchneria teres (432–3660 m).

Androsova’s type specimen (ZIN-1/3670) in Zoological Institute of the Russian Academy of Sciences (ZIN RAS), colony collected southwestern region of Sakhalin, Moneron Island (Kaibato), Sea of Japan, 36 m depth, (examined by micrographs); large erect colonies and fragments (NSMT Te-724 to Te-734; ZIHU 4130 and 4131), collected SE of Akkeshi Bay (42°48.37'N, 144°56.22'E) by M. Hirose from research boat Misago-maru, 6 July 2010, 116 m depth, by dredge; large erect colony and fragments (NSMT Te-790 to Te-794) collected SE of Akkeshi Bay (42°48.20'N, 144°55.43'E to 42°48.26'N, 144°54.91'E) by M. Hirose from research boat Misago-maru, 8 July 2011, 114−116 m depth, by dredge.

ZL, 0.558−0.921 (0.751±0.101); ZW, 0.408−0.882 (0.611±0.088); n=25. OrL, 0.135−0.223 (0.189±0.019); OrW, 0.130−0.226 (0.192±0.023); n=27. OvL, 0.124−0.444 (0.247±0.072); OvW, 0.104−0.395 (0.214±0.056); n=44.

Colony erect, rigid, robust, with thick, broad, strap-like branches at least 10 zooid widths across, or foliaceous, fan-shaped lobes; lobes or branches 0.86 to 8.04 cm wide (2.15±1.38 cm, n=25), multifurcate or irregularly lobed on distal margin; zooids open on both sides (Fig. 9). Broad lobes of some colonies are covered with conspicuous, closely spaced circular monticules (Fig. 9B). Autozooids oval, rounded hexagonal, or subrectangular in outline; strongly convex frontally, arranged in quincunx, zooecial borders indistinct; frontal shield tessellated, with four to eight areolar pores of irregular size along margin or offset more centrally (Fig. 10A, B). Orifice (Fig. 10C, D) semicircular, broader than long, slightly concave proximally, lyrula and condyles absent (Fig. 10D); deeply immersed with age. Oral spines lacking. Peristome deep, cormidial, formed by contributions of secondary calcification from distal and lateral zooids, with suture lines often evident between the sectors (Fig. 10E). Suboral avicularia approximately same size as orifice, located at margin of peristome; oval, with complete or incomplete pivot, rostrum slightly elevated distally, with a median tooth; mandible semicircular, directed proximally or proximolaterally (Fig. 10B, C). Rounded conical tooth on oral edge of avicularian rostrum conspicuous, projecting into secondary orifice (Fig. 10E). Hypertrophied suboral avicularia are frequent; often larger in area than orifice; distal end of rostrum elevated, pointed; rounded-triangular mandible directed proximally (Fig. 10B, C). I observed no other types of avicularia. Basal part of colony robust, composed of both interzooidal kenozooids and autozooids, borders indistinct. Ooecium imperforate, smooth, completely immersed by secondary calcification from the neighboring zooids, the proximal margin of the ooecium distinctly indented laterally and centrally, obscuring the distal edge of primary orifice in ovicellate zooids (Fig. 10E). Frontal budding frequent (Fig. 10F).

Moneron Island, SW Sakhalin, 36 m depth (Androsova 1958); off Akkeshi Bay, Hokkaido, 114–116 m depth (this study).

My material matches Androsova’s (1958) description of Porella variabilis. She mentioned that the tooth on the proximal margin of the peristome is associated with the suboral avicularium, and that the tooth is present when the avicularium abuts the proximal margin of the peristome, but absent when the avicularium is offset proximally from the peristome. This is the case in all known species of Buchneria. Androsova (1958) reported Buchneria variabilis from 36 m depth, shallower than my specimen from 114–116 m near Akkeshi. This apparent difference in the bathymetric distribution between Sakhalin and Akkeshi may be related to water temperature, as Sakhalin is more northern and colder than Akkeshi.

Buchneria variabilis differs from Buchneria teres and Buchneria rhomboidalis in colony form and in having larger suboral avicularia.