Holotype– Female, locality U, slide mounted. Paratypes– locality U, 15 on slides, 3 in alcohol.

USA, Vermont, Chittenden Co., South Burlington, University of Vermont Constructed Wetland, N 44.45869 W 73.18936.

The new species is dedicated to Ross Bell in celebration of his contributions to our understanding of the entomological fauna of Vermont.

Length to 0.5 mm. Live individuals black, alcohol preserved specimens (Fig. 1) purple, with pigment more or less uniformly distributed throughout head, body and antennae, legs and manubrium purplish brown. Ant. 4 without basal microsensilla, with 8-9 well developed thin-walled sensilla, and 2-3 additional poorly developed sensilla distributed along distal 2/3 of segment; subapical sense organ with 1 differentiated microsensilla and 1 microrod in a pit. Ant. 3 with 0-1 basal microsensilla; sense organ with 2 clubbed sensilla and 2 differentiated guard sensilla; 1 lateral sensilla present. Ant. 2 with 2 basal microsensilla and 1 distal sensilla. Ant. 1 with 2 basal microsensilla, and 1 whorl of hairs comprising 11 acuminate setae and 2 sensilla. Eyes 8+8, H slightly smaller or subequal to C (Fig. 2), with 3 interocellar setae; PAO circular to elliptical, about 1-1.7X diameter of eye B, and 3 associated setae. Prelabral and labral chaetotaxy 2/554; distal labral margin smooth. Papilla of outer maxillary lobe bifurcate, sublobal plate with 2 appendages. Maxilla with lamella 1 narrow, surpassing tip of capitulum and ciliate only along external margins. Labial palps with a full complement of papillae and 3 proximal setae; papillae E with blunt lateral process and 6 guard setae, e7 absent; labial triangle with 5 anterior and 4 posterior setae; distribution of postlabial setae in columns I, C, E and L as 3, 3, 1, 3/4 (Fig. 3). Body dorsally covered by smooth hairs; some hairs on the pre-posterior row reaching base of setae on posterior row; tergal macrochaetae undifferentiated; thorax without ventral setae. Axial setae on Th. 2-Abd. 3 as 5-6, 4//3, 3, 3; Th. 3 with 14-16 setae on posterior row; microsensillar and sensillar formulae 10//101 and 33//22224, respectively (Figs. 5-6); antero-lateral sensilla on Th. 2 anterior to microsensilla, lateral sensilla on Th. 2-3 anterior to medial sensilla; medial thoracic sensilla inserted on preposterior row of setae, abdominal sensilla inserted just anterior or on posterior row of setae; lateral sensilla on Abd. 5 similar to medial sensilla (Fig. 6). Proximal and medial subcoxae on legs 1-3 with 1, 1; 1, 5; 3, 5-6 setae. Lateral valve of Abd. 6 with 1 hr seta (Fig. 4). Tibiotarsi on legs 1-3 with 20, 20, 22 setae, respectively; tibiotarsal whorl B with B4/5 (Fig. 7); only male seen apparently in reproductive quiescent instar, without modified metatibiotarsal setae; legs 1-3 with 1, 2, 2 clearly capitate tenent hairs (Fig. 11). Unguis and unguiculus toothless, unguiculus lanceolate or acuminate. Ventral tube with 4+4 apical and 1+1 posterior setae. Tenaculum with 3+3 teeth and 1 seta. Anterior and posterior furcal subcoxae with 8-11 and 4-5 setae, respectively. Proportion manubrium/dens/mucro as 3/2/1. Manubrium with 13 dorsal and 0 ventral setae (Fig. 10). Dens weakly tuberculate, with 11 (12) dorsal (Fig. 9-10) and 5 (4/6) ventral setae (Fig. 8, 10). Mucro bidentate, with a pronounced basal membrane (Figs. 12-13).

Following Potapov (2001), Ballistura rossi sp. n. is most similar to Ballistura hankoi (Stach), 1929 from which it can be distinguished (Table 1) by the number of dorsal manubrial setae (13 in rossei, 20 in hankoi), number of setae around the PAO (3 in rossei, 2 in hankoi), and number of dorsal setae on dens (11-12 in rossi, 10 in hankoi). Ballistura tuberculata (Stach), 1947 (if this is really different from Ballistura hankoi) can be separated from Ballistura rossi by the same characters of the furcula and PAO as Ballistura hankoi, and by coloration (pale blue-grey in tuberculata, dark purple in rossi), size (largest individual of rossi is 0.5 mm whereas tuberculata reaches 0.9 mm) and, possibly, shape of the basal membrane of the mucro (wider at middle in rossi, wider on basal half in tuberculata). Other chaetotaxic characters may distinguish these three species, but practically nothing has been published about the chaetotaxy Ballistura hankoi or Ballistura tuberculata (Potapov 2001).

Christiansen and Bellinger (1998) reported Ballistura tuberculata from Indiana and Nova Scotia, but whereas the relatively large size of those individuals (up to 0.8 mm) support the determinationas tuberculata, the relative size of the OPA and shape of the mucronal membrane suggest similarities to hankoi. The specimens from Vermont fit the general description provided by Christiansen and Bellinger (1998) for Ballistura tuberculata, except for the larger number of dorsal setae on the dens and the smaller size of the Vermont specimens (Table 1).

Ballistura rossi sp. n. appears to be unique among Ballistura sp. in having 2 instead of 3 appendages in the sublobal plate of the outer maxillary lobe. However, this character has been reported in relatively few of the species currently placed in Ballistura and further information is needed to determine how unique the condition in Ballistura rossi sp. n. is.

Holotype– Locality G, Male, slide mounted. Paratypes– Locality G, 3 on slides, 3 in alcohol; H, 2 on slides, 2 in alcohol. Other Material– Locality F (9 in alcohol),

USA, Vermont, Grand Isle Co., South Hero, White’s Beach, N44.62189 W73.32273.

This species is dedicated to Joyce Bell for her contributions and support to the study of the arthropod fauna of Vermont.

Length to 1.2 mm. Living individuals black, alcohol preserved specimens dark purplish brown to black, with pigment more or less uniformly distributed through out head, body and antennae, legs and manubrium purplish (Fig. 14); some individuals with paired black longitudinal lines extending from Th. 2-Abd. 3. General body shape short and stout, with sudden bend between Abd. 4-5 (Fig. 14) as in Folsomides. Ant. 4 without basal microsensilla (bms of Potapov 2001), with at least 13 well-developed thin-walled sensilla, and 14 other sensilla distributed along the length of the segment; subapical sense organ with 1 differentiated microsensilla and 1 microrod in a pit (Fig. 16). Ant. 3 with 1 poorly differentiated basal microsensilla; sense organ with 2 clubbed sensilla and 2 differentiated guard sensilla; 1 lateral sensilla present; females with 9-10, and males with up to 16 additional sensilla distributed mostly on dorsal face of segment. Ant. 2 with 3 basal microsensilla; and 1-2 distal sensilla. Ant. 1 with 2 basal microsensilla, 17-18 smooth, acuminate setae, and 2-3 sensilla. Eye patch with 8+8 subequal eyes and 3 interocellar setae; PAO elliptical, about 2X diameter of eye B, and 4-5 associated setae (Fig. 17). Prelabral and labral chaetotaxy 2/554; distal labral margin smooth. Papilla of outer maxillary lobe simple, sublobal plate with 4 appendages. Maxilla with lamella 1 narrow, with cilia only along margins, surpassing tip of capitulum. Labial palps with a full complement of papillae and 3 proximal setae; papillae E with lateral process and 6 guard setae, seta e7 absent (Fig. 18a-b); labial triangle with 5 anterior and 4 posterior setae; distribution of postlabial setae in columns I, C, E and L variable 4(5-6), 3/5 (1, 6), 2-3, 5(4) (Figs. 20-22). Body dorsally covered by smooth hairs; some hairs on the pre-posterior row reaching base of setae on posterior row; tergal macrochaetae undifferentiated; thorax without ventral setae. Axial setae on Th. 2-Abd. 3 as 7-9; 7-8(9)//5(4/6-7); 5(3-4/6); 5. Th. 3 with 28/33(20) setae on posterior row; microsensillar formula 10(1)//101; sensillar formula variable, often asymmetric 14(17-18); 9-13//9(8/10); 8(9); 9(5/8/10); 11-19; 12(4/8/14/16) (Fig. 15); antero-lateral sensilla on Th. 2 posterior to microsensilla, but spatial relation among lateral sensilla variable between individuals; lateral sensilla on Th. 2-3 anterior to medial sensilla; medial thoracic sensilla inserted on preposterior row of setae, insertion of abdominal sensilla variable, just anterior or on posterior row of setae, or clearly anterior to subposterior row (Fig. 15); all sensilla on Abd. 5 similar in size. Proximal and medial subcoxae on legs 1-3 with 1, 0; 5-8, 4-9; 6-12, 6-15 setae. Lateral valve of Abd. 6 with 3 hr setae (Fig. 19). Ventral thoracic setae absent. Sculpturing of thoracic sterna smooth. Tibiotarsi 1-3 with 24, 27, 30 setae; tibiotarsal whorl B complete, with B5 clearly thicker and longer than B4 (Fig. 26); adult males with setae B5 and x truncate (Fig. 23); legs 1-3 with 1 (A1), 2 (A1, A7), 2 (A1, B7) capitate or acuminate tenent hairs (Fig. 27). Unguis and unguiculus toothless, unguiculus triangular. Ventral tube with 6-11 disto-lateral and 6-9 posterior setae. Tenaculum with 3+3 teeth and 1 seta. Sterna of Abd. 3 without isolated field of setae. Anterior and posterior furcal subcoxae with 9-19 and 4-11 setae, respectively. Proportion manubrium/dens/mucro as 3/2/1. Dens smooth, and cylindrical (Fig. 25). Chaetotaxy of manubrium and dens as in Fig. 28: manubrium with 5-8 basal setae, 15-24 dorsal and 0 ventral setae; dens with 18-20 (15/26) dorsal and 5 (4/6) ventral setae. Mucro with wide lamella, without basal notches, clearly separated from dens; bidentate, teeth subequal (Fig. 24a-b).

Three individuals show variation in the number and size of eyes. In the small juvenile eyes G and H are small, barely rising above the cuticle; one male is blind; and in one female all eyes in one patch are subequal, but on the other patch eye E is less than half the size of F. The axial setae are often disorganized and the number of setae in a column is open to interpretation. The number of tergal sensilla is variable. Most individuals have an asymmetric number of sensilla, and two individuals lack the microsensilla of Abd. 1 on one side. Tenent hair B7 on metathoracic legs often appears acuminate instead of capitate. Two individuals have 3+4 tenacular teeth.

The generic placement of the new species is problematic. It better fits in the genus Subisotoma (Table 2), but it is unique among species currently assigned to that genus in having more than 8+8 tergal sensilla on each segment, by the significantly larger number of dental setae (most Subisotoma species have 4 or fewer dorsal and 1-2 ventral setae, whereas Subisotoma joycei has 18-20 dorsal and 4-6 ventral setae), and by having a well developed furcula with mucro exhibiting a wide lamella and clearly separated from the dens. Subisotoma joycei is similar to species in the genus Isotopenola Potapov, Babenko, Fjellberg & Greenslade, 2009 in the presence of sensillar polychaetosis on body terga, but differs from all forms in that genus by having smooth thoracic sterna, lacking an isolated field of setae on Abd. 3 sterna and in the number of guard setae on labial papilla E. The strong polychaetotic furcula in Subisotoma joycei resembles the condition in Ballistura, but the new species clearly differs from Ballistura in maxillary palp structure, sensillar and microsensillar formulae, presence of a full complement of setae in tibiotarsal whorl B, and dens sculpturing (Table 2).

The new species is most similar to Ballistura ewingi James, 1933, sensu Folsom (1937) from which it differs in aspects of color pattern (trunk ventrally white in ewingi, dark purple brown in joycei), the number of tenent hairs (2-3 on all legs in ewingi, 1, 2, 2 in joycei), number of distal seta on ventral tube (4 on ewingi, 11 in joycei), and number of tenacular teeth (2 in ewingi, 3-4 in joycei). The new species may be the same as the Pennsylvania specimens preliminarily assigned to Ballistura ewingi by Christiansen and Bellinger (1998), although this form also seems to have considerably fewer distal setae on the ventral tube than S. joycei sp. n.(Table 3). Ballistura ewingi has been described as having smooth dens, and probably does not belong in Ballistura, which Potapov (2001) restricts to species with tuberculate dens. Important characters needed to determine the appropriate generic placement of Ballistura ewingi remain undescribed and require the study of fresh material.

The new species is also similar to Ballistura excavata Folsom, 1937, but the two species are easily separated by body color, eye number, shape of tenent hairs and unguiculus, and structure of the dens (Table 3).

Holotype– Female, slide mounted, locality B. Paratypes– Locality B, 9 individuals on slides, 1976 in alcohol; N, 5 mounted on two slides and more than 3000 in alcohol; P, 4 individuals on slides and 59 in alcohol; Other material– Locality A, 800 individuals in alcohol; C, 7 in alcohol; D, 187 in alcohol; E, 30 in alcohol; F, 32 in alcohol; G 1186 in alcohol; H, 1290 in alcohol; J, 158 in alcohol; K, 35 in alcohol; L, 1723 in alcohol; M, 1555 in alcohol; Q, 5 in alcohol; R, 2 in alcohol; S, 1 in alcohol; T, 8 in alcohol.

USA, Vermont, Chittenden Co., Burlington, Pine Street Canal, near water treatment plant at south end of Battery St., N 44.46859 W 73.21901

The species is named after ‘Champ’ the denizen monster of Lake Champlain, were the new species seems to be most abundant.

Length to 0.7 mm. Live specimens black, alcohol preserved individuals (Fig. 29) dark purple, with pigment more or less uniformly distributed throughout head, body and antennae; legs and manubrium light purplish brown. Ant. 4 with 1 basal microsensilla, and 7 poorly differentiated thin-walled sensilla distributed along apical half of segment; subapical sense organ with 1 poorly differentiated microsensilla and 1 micropeg in a pit. Ant. 3 with 1 basal microsensilla; sense organ with 2 clubbed sensilla and 2 differentiated guard sensilla; 1 lateral sensilla present; males with 2 additional dorsal sensilla. Ant. 2 with 3 basal microsensilla and 1 distal sensilla. Ant. 1 with 2 basal microsensilla and 1 whorl comprising 11 setae and 2 sensilla. Eyes 8+8, G and H slightly smaller than others (Fig. 30), with 3 interocellar setae; PAO elliptical, about 2.3X diameter of eye B, with 4-5 associated setae. Prelabral and labral chaetotaxy 4/554; distal labral margin smooth. Papilla of outer maxillary lobe bifurcate, sublobal plate with 4 appendages (Fig. 31). Maxilla with lamella 1 narrow, surpassing the tip of capitulum, with cilia confined to external margins (Fig. 32). Labial palps with a full complement of papillae and 3 proximal setae; papillae E with blunt lateral process and 7 guards, e7 detached from papilla (Fig. 34); labial triangle with 5 anterior and 4 posterior setae; distribution of postlabial setae in columns I, C, E and L as 4, 3, 2, 3 (Fig. 35). Body dorsally covered by smooth hairs; some hairs on the pre-posterior row reaching base of setae on posterior row; thorax without ventral setae; axial setae on Th. 2-Abd. 3 as 6-8, 6-7//4-5, 4-5, 4-5; Th. 3 with 20-22 setae on posterior row; microsensillar and sensillar formulae 11//111 and 33//22224, respectively (Figs. 33, 36); lateral sensilla on Abd. 5 swollen (Fig. 36), all sensilla inserted anterior to posterior row of setae, tergal macrochaetae smooth, poorly differentiated, distributed as 11//11124; Abd. 5≈ 3.2X medial macrochaeta. Proximal and medial subcoxae on legs 1-3 with 1, 1; 3(4), 6(7); 5(4, 6, 7), 7(6, 8) setae (Fig. 38). Lateral valve of Abd. 6 similar to Ballistura joycei, with 3 hr setae. Tibiotarsal whorl B complete; male metatibiotarsal setae x and B5 thin, short, bothriotrica-like, with modified sockets (Fig. 37); legs 1-3 with 1, 2, 2 tenent hairs as in Ballistura joycei, but all tenent hairs acuminate, A1 on L2 sometimes appearing weakly clubbed. Unguis and unguiculus toothless (Fig. 37). Ventral tube with 3+3 apical setae, posterior face with 1 basal and 4 distal setae. Tenaculum with 4+4 teeth and 1 seta. Anterior and posterior furcal subcoxae with 12-18 and 7-8 setae, respectively. Proportion manubrium/dens/mucro as 6/4/1. Chaetotaxy of furcula as in Figure 39: manubrium with 17-18 dorsal and 1 ventral setae; dens weakly crenulated, with 9 dorsal and 6 ventral setae. Mucro bidentate, subapical tooth longer than apical (Fig. 40).

Scutisotoma champi sp. n. is unique among Scutisotoma species in having a lamelate bidentate mucro, 4 tenacular teeth, 9 dorsal and 6 ventral setae on dens, and maxillar lamela 1 longer then the capitulum. The new species is most similar to the Central Asian Scutisotoma acorrelata Potapov, Babenko & Fjellberg, 2006 and Scutisotoma tenuidentifera Potapov, Babenko & Fjellberg, 2006, from which it can be distinguished by the characters listed in Table 4. Among North American species, Scutisotoma champi sp. n. is most similar to Scutisotoma titusi (Folsom), 1937 from which it can be easily distinguished by the number of ventral setae on dens and the number of tergal sensilla on Abd. 4 and 5 (2+2, 4+4 in champi, 7-8+7-8, 8-12+8-12 in titusi).

Scutisotoma champi sp. n. is the most common species found in sandy beaches on the northern 2/3 of Lake Champlain as well as Lake Willoughby and Greater Averill Pond, and it is likely present in most if not all lakes and large ponds in northern Vermont and southern Quebec. The species was collected in apparently healthy beaches (e.g., Pearl Bay, locality H), as well as on highly disturbed, strongly compacted beaches (e.g., Colchester Beach, locality C). The species is most abundant in beaches with aquatic plant litter, but it is also found in sand in beaches without visible surface plant remains.

USA, Vermont, Chittenden Co., Bolton, Camel’s Hump ≈1200-1230 m elevation, 7 August 1972, W. Rittenhouse, coll. Two slides, one with three individuals, the other with one individual. These are the individuals originally determined as Ballistura alpa by Bellinger (1982).

The following notes serve as a complement to the original description. Cuticle covered by many secondary granules. Organite of Ant. 4 capitate, guard sensilla not strongly modified (Fig. 42). Ant. 3 sense organ, lateral and supplementary sensilla as in Fig. 43. Ant. 2 with 1 distal sensilla and at least 1 basal microsensilla. Ant. 1 with 2 weakly modified basal microsensilla, 3-4 sensilla, and 12-14 setae. Eye patch with 3 setae, PAO with 2 guard setae. Labral formula 4/5, 5, 4. Apical seta of outer maxillary lobe bifurcate, sublobal plate with 4 appendages. Maxillary lamellae not clearly seen, but lamella 1 apparently surpassing tip of capitulum and apically acuminate (lateral margins converging well before tip of lamella), with cilia only along lateral margins. Labial papilla E with 7 guard setae, e7 detached from papilla as in Scutisotoma champi. Labial triangle with 5 anterior and 4 posterior setae. Postlabium with 3(4), 2, 1, 3 setae in columns I, C, E and L, respectively (Fig. 44). Body setae smooth and short, tip of seta on anterior rows not reaching base of setae on posterior rows. Thoracic sterna without hairs. Axial setae on Th. 2-Abd. 3 as 3-4, 5//4, 2-3, 2-4; Th. 3 with 18-20 setae on posterior row; microsensillar and sensillar formulae as 11//111 and 8(10)8//7758(9)7, respectively (Fig. 41); Th. 2 with 2 lateral sensilla inserted anterior to medial sensilla; medial sensilla on all segments inserted on p-row; Abd. 5 sensilla not swollen. Tergal macrochaetae undifferentiated. Proximal and medial subcoxae on legs 1-3 with 1, 0; 4(5), 4; 5(7), 4 setae. Lateral valves of Abd. 6 similar to Ballistura rossi, with 1 hr seta (Fig. 46). Tibiotarsal whorl B complete; legs 1-3 with 1, 2, 2 tenent hairs, all acuminate. All unguis with 1 inner tooth; unguiculus toothless, without terminal filament. Ventral tube with 7+7 apical setae, posterior face with 2 basal and 4 distal setae. Tenaculum with 4+4 teeth and 1 seta. Anterolateral, anteromedial and posterior furcal subcoxae with 7/8(6, 10), 11 (12, 13) and 7-11 setae, respectively (Fig. 47). Manubrium with 15 dorsal and 0 ventral setae. Dens granulate, with 7-8 dorsal and 6 (5) ventral setae. Mucro bidentate, subapical tooth longer than apical (Fig. 45).

This species was originally placed in the genus Ballistura, but the presence of a complete whorl B on pro- and mesothoracic legs and four prelabral setae excludes it from that genus (Potapov 2001). The presence of secondary granules on the cuticle in combination with a well developed furcula and the insertion of the medial and almost all other tergal sensilla on Th. 2-Abd. 3 on the posterior row of setae place this species in the genus Pachyotoma. In the original description of the species Christiansen and Bellinger (1980) indicate the presence of 5 distal setae on the ventral tube and a toothless unguis. The individuals from Vermont have 7 distal setae on the ventral tube and one distinct inner tooth on all unguis and may represent a distinct species.