Caracladus tsurusakii Saito, 1988

(Figs 40–46)

Caracladus tsurusakii Saito, 1988: 21, figs 11–15.

Type material. HOLOTYPE: Japan: Hokkaido: Kuttyuan-cho, Abuta-gun, Youtei-zan mountain [42°52'30'' N, 140°39'30'' E], 1♂ 25.ix.1981, leg. N. Tsurusaki, S. Nakano, S. Sasaki (NSMT Ar5249, examined) (Saito 1988). PARATYPES: Japan: Hokkaido: Kuttyuan-cho, Abuta-gun, Youtei-zan mountain [42°52'30'' N, 140°39'30'' E], 1♀ 25.ix.1981, leg. N. Tsurusaki, S. Nakano, S. Sasaki (NSMT Ar5250, examined) (Saito 1988); Kuttyuan-cho, Abuta-gun, Youtei-zan mountain [42°52'30'' N, 140°39'30'' E], 1♂ 25.ix.1981, leg. N. Tsurusaki, S. Nakano, S. Sasaki (Saito 1988) .

Diagnosis. Males: Most similar to C. avicula with differences in the structure of the male palp (Saito 1988). Cephalic lobe similar to C. avicula but more robust and lacking a neck. Embolus whip-like as in C. avicula but much longer and with a loop back, radical tailpiece long and bent (Fig. 41). Distal suprategular apophysis blunt and nearly transparent (Fig. 41). Palpal tibia with two well defined apophyses (Fig. 42).

Females: Nearly triangular dorsal plate with two copulatory pouches anterior and ventral to it and together not broader than the anterior end of the dorsal plate (Fig. 40).

Description. Male (holotype, NSMT Ar5249): Total length: 2.50 mm. Cephalothorax: chestnut brown with darker radiating lines, cervical grooves black (Saito 1988); 1.03 mm long without cephalic lobe (Fig. 45), 1.35 mm long with cephalic lobe (Fig. 45); 0.78 mm wide. Cephalic lobe: projecting forward, thick at base and sharply pointed tip with sparse stout hairs; at thinnest part below the eye-field 0.14 mm wide laterally, 0.23 mm wide dorsally (Figs 43, 45); sulcus absent (Fig. 44). Eyes: PME upmost on the cephalic lobe, separated by slightly less than 1.5 times their diameter; position of the PLE adjacent to and above the ALE; one long macroseta projecting forward between AME (Fig. 45); anterior row slightly procurved, eyes separated by their radius. Clypeus: wide, slightly convex. Chelicerae: dark brown (Saito 1988); promargin with five teeth; retromargin with six denticles; many broad stridulatory striae. Sternum: yellowish brown, strongly darker at the margins (Saito 1988). Legs: tibia I–IV with one dorsal proximal macroseta (1-1-1-1); Tm I: 0.63. Pedipalp: prolateral tibial apophysis glabrous, facing forward; retrolateral tibial apophysis hairy, facing forward (Saito 1988: Fig. 12); suprategular apophysis semi circular; marginal suprategular apophysis minute; distal suprategular apophysis thin, blunt (Fig. 41); embolic membrane with papillae; radix simple without any processes other than the long radical tailpiece and the very long, whip-like embolus that is strongly curved towards the tip (Fig. 41).

Female (paratype, NSMT Ar5250): Total length: 2.58 mm. Cephalothorax: 1.08 mm long; 0.83 mm wide; general appearance similar to males, but without cephalic lobe (Saito 1988). Eyes: anterior row slightly recurved, separated by about the radius of the AME; posterior eyes separated by at least an eye diameter (Saito 1988). Epigyne: dorsal plate visible in ventral view; receptacula lateral to the dorsal plate, barely visible in transparency trough ventral plate (Fig. 40); very small copulatory pouches (Fig. 40). Vulva: without copulatory duct (Fig. 40); receptacula globular.

Distribution. Only known from the type locality on Hokkaido, Japan (Saito 1988).

Habitat. The specimens were collected under leaf litter by sifting or with pitfall traps (Saito 1988). If we correctly located the locus typicus, this species occurs on a volcano on ca. 1300 m a.s.l.

Phenology. One record from late September, only.

Remarks. C. tsurusakii lacks a copulatory duct. The insertion of sperm is assumed to take place through a space between the ventral and the dorsal plates which are supposed to be pressed apart during copulation.