Metatrachelas, Bosselaers, Jan & Bosmans, Robert, 2010

Bosselaers, Jan & Bosmans, Robert, 2010, Studies in Corinnidae (Araneae): a new Paratrachelas Kovblyuk & Nadolny from Algeria, as well as the description of a new genus of Old World Trachelinae, Zootaxa 2612, pp. 41-56 : 47-49

Metatrachelas gen. n.

Figs. 3 A–C .

Type species: Trachelas rayi Simon, 1878

Diagnosis. Metatrachelas differs from T. minor , the type species of Trachelas , by the presence of a chilum, a smooth carapace with a broad cephalic part, the absence of an abdominal do scutum in males, a male palp without ve femoral groove or RPA and possessing a blunt RTA and an oval bulbus with a short apical embolus, an epigyne with a medially situated, wide epigynal hood as well as median COs connected to short and straight IDs, as opposed to the anterior COs and thin, coiled IDs connected to a longitudinally oriented median stretch ("median ducts of epigyne" of Kovblyuk & Nadolny (2009)) in T. minor and related species, as well as large anterior oval to piriform ST2, and dumbbell-shaped ST1 of which the two globular lumina are interconnected by a thin, straight canal.

Metatrachelas differs from Paratrachelas by its smooth carapace and subrectangular PME, absence of an abdominal do scutum as well as absence of leg cusps in males, a male palp with an oval bulbus without conductor, an RTA which is short and blunt instead of long and pointed, a medially situated epigynal hood, dumbbell-shaped as opposed to sausage-shaped ST1 with a straight internal duct and anteriorly situated ST2 which are larger than ST1.

Description. Small (2.5–5.2) spiders. Carapace brown, almost smooth ( Fig. 3A–B ), cephalic part wide, especially in males. A short but distinct fovea in posterior third. Chilum single and subtriangular, sclerotised, brown. PLB a very narrow strip above each coxa, connected with posterior end to blunt subtriangular sclerites situated between coxae, as such consisting of two consecutive brown, sclerotised, long strips. Eyes in two transverse rows of four, both procurved in frontal view and recurved in dorsal view. All eyes subequal, PME subrectangular. MOQ widest posteriorly. Clypeus slightly smaller than diameter of AME. Chelicerae brown, rugose, with pronounced cheliceral boss. Promarginal cheliceral rim with three teeth, increasing in size towards fang base, retromarginal rim with two subequal teeth. Fangs sickle-shaped. Sternum shield shaped, smooth and shining, brown. Small and pointed PCT, ICS blunt. PSP surrounding ventral half of petiolus, brown and sclerotised, subtriangular. Labium subtrapezoidal, as long as wide, length 3/4 of endite length. Endites subrectangular, frontally rounded, with apical hair tuft and serrula, no oblique depression. Legs unicolorous yellow, spineless and without leg cusps, no rh, no trochanter notch. Patellar indentation narrow, 1/ 2 of patella length. Leg formula 4123 in females, 4123 or 1423 in males. Dense ve bristles on ti, mt and ta of legs I and II in females. Dense ve terminal preening brush on mt III and IV in both sexes. Tarsi with two claws and claw tufts. Abdomen oval, longer than wide, brown or grey with a pattern of patches and chevrons, no dorsal scutum in males. Male palp with a short and blunt RTA, and an oval bulbus with a short apical embolus, conductor absent. Sperm ducts partly discernable through transparent cuticle.

Epigyne poorly sclerotized, with a central depression anteriorly bordered by a wide arc-shaped hood enclosing the COs. The large, anteriorly situated, oval to piriform ST2 are clearly visible through the transparent cuticle (Bosselaers et al. 2009: figs. 25, 26, 32, 35, 36).

Vulva has two large oval to piriform ST2 anterior to the arc-shaped epigynal hood ( Fig. 3C ). Immediately posterior to the hood are the medially situated COs connected to a wide and short ID. ST1 consists of two globular lumina interconnected by a thin straight canal. The smaller of both lumina is connected to the long, tapering FD, the larger one communicates with the ID.

Etymology. The genus name is derived from the Greek µετα, in between, in the middle, and the genus Trachelas , and refers to the position of the new genus on the preferred cladogram, in between T. minor and Paratrachelas .

Composition of genus. The new genus consists of M. rayi new combination, M. macrochelis new combination and M. amabilis new combination, three species recently redescribed and illustrated in Bosselaers et al. (2009), all formerly placed in Trachelas .

Figures

FIGURE 3 A – C. Metatrachelas rayi. D – F, H. Paratrachelas acuminus. G, H. Paratrachelas atlantis. A, male, MNHN- 1523 do; B, female, MNHN- 1523 do; C, vulva, ve; D, male allotype, do; E, female holotype, do; F, vulva, ve; G, male holotype, do; H, male palps of P. acuminus (left) and P. atlantis, pl, ve and rl. Scale bars: A – B, D – E, G: 1; C, F: 0.1; H: 0.25.