Endonura ossetica sp. nov.

Figs 57–66, Tab. 7

Type material. Holotype: adult female on slide, Russia, Caucasus, Northern Ossetia, Tseyskoye Canyon, Verkhniy Tsey, near turistic base, maple forest, litter, 16.IX.1990, leg. M. Potapov (MSPU) . Paratype: juvenile on slide, same data as holotype (DIBEC) .

Etymology. The species name refers to geographic area where it was found – the Republic of Northern Ossetia.

Diagnosis. Habitus typical of the genus Endonura . Dorsal tubercles present and well developed. 2+2 eyes darkly pigmented. Buccal cone long, labrum ogival. Head with chaetae A, B, C, D, E, F and G. Chaeta O absent. Tubercles Cl and Af separate. Tubercles Dl and (L+So) on head with 6 and 8 chaetae respectively. Tubercles Di and De on th. I fused. Tubercles De on th. II and III with 3 and 4 chaetae respectively. Tubercles L on abd. III and IV with 4 and 7 chaetae respectively. Abd. IV and V with 8 and 3 tubercles respectively. Claw without inner tooth. Tibiotarsi with relatively long chaetae B4 and B5.

Description. Habitus typical of the genus. Body length (without antennae): 0.75 (juvenile)–2.47 mm (holotype: 2.47 mm). Colour of the body white. 2+2 large dark-pigmented eyes (Figs 57, 58).

Types of dorsal ordinary chaetae. Macrochaetae Ml slightly thickened, relatively long, straight or arc-like, narrowly sheathed, feebly serrated, apically rounded or pointed (Figs 57, 58, 63, 65, 66); macrochaetae Mc and Mcc thickened, straight, pointed or apically rounded; mesochaetae and microchaetae short, thin and pointed.

Head. Buccal cone long. Labrum ogival, with ventral sclerifications as in Fig. 61. Labrum chaetotaxy 4/2, 4. Labium as in Fig. 62. Maxilla and mandible as in Figs 59, 60. Antennal segments I and II with 7 and 11 chaetae respectively. Chaetotaxy of antennal segments III and IV impossible to recognize. Apical vesicle poorly visible, probably trilobed. Chaetotaxy of head as in Tab. 7 a, b, and Figs 57, 58. Tubercle Af on head longer than tubercles Oc. Tubercle Af with chaetae D and E (Fig. 58). Elementary tubercles CD and BE present. Chaeta A shorter than B.

Thorax, abdomen, legs. Body s-chaetae thin and smooth, notably shorter than nearby macrochaetae (Figs 57, 63, 65, 66). Chaetotaxy of thorax and abdomen as in Tab. 7 c and in Figs 57, 63, 65, 66. Tubercles Di on th. I differentiated and fused with De (Fig. 57). Chaetae De3 on th. III and abd. I–III as Mcc. Chaetae De3 on th. III (Fig. 63) and abd. I free. The line of chaetae De1-chaeta s parallel to the dorsomedian line on abd. I–III. Tubercles Di on abd. V fused, with chaetae Di3 as MCC or mi (Fig. 65). Furca rudimentary without microchaetae. Chaetae L' and Vl on abd. V present. Cryptopygy slightly developed, abd. VI visible in dorsal view (Fig. 65). Chaetotaxy of legs as in Fig. 61 and Tab. 7 c. Claw without inner tooth (Fig. 64).

b) Cephalic chaetotaxy–ventral side.

c) Postcephalic chaetotaxy.

Terga Legs

Di De Dl L Scx2 Cx Tr Fe T th. I 3 1 - 0 3 6 1 3 1 9 th. II 3 2+s 3+s+ms 3 2 7 6 12 19 th. III 3 3+s 3+s 3 2 8 6 1 1 1 8

Sterna

abd. I 2 3+s 2 3 VT: 4

abd. II 2 3+s 2 3 Ve: 5; chaeta Ve 1 present

abd. III 2 3+s 2 4 Vel: 4–5; Fu: 5 me, 0 mi

abd. IV 2 2+s 3 7 Vel: 4; Vec: 2; Vei: 2; Vl: 4

abd. V (3+3) 7+s Ag: 3; Vl: 1

abd. VI 7 Ve: 13; An: 2mi

Remarks. An unusual shape of tubercle Af which is connected with chaetae D and E places the new species in an isolated position within the genus. Viewing the key below, E. ossetica sp. nov. seems to be most similar to E. urotuberculata Pomorski & Skarżyński, 2000, a taxon described from Bulgaria (Pomorski & Skarżyński 2000). Nevertheless, besides the character mentioned above, these forms differ in a number of features: presence/absence of eyes (present in ossetica, absent in urotuberculata), shape of labrum (ogival in ossetica, nonogival in urotuberculata), presence/absence of tubercle Di on head (present in ossetica, absent in urotuberculata), number of chaetae (L+So) on head (8 in ossetica, 9 in urotuberculata), presence of fusion of tubercles Di and De on th. I (present in ossetica, absent in urotuberculata), presence/absence of free chaeta De2 on th. II–III (absent in ossetica, present in urotuberculata), presence/absence of cauliflower-like tubercles on abd. V–VI (absent in ossetica, present in urotuberculata) and presence/absence of microchaetae on furcal remnant (absent in ossetica, present in urotuberculata).

Ecological note. The species was collected in litter of maple forest.