Ballomma, Jocqué, Rudy & Henrard, Arnaud, 2015

Jocqué, Rudy & Henrard, Arnaud, 2015, Ballomma, a new Afrotropical genus in the Cryptothelinae (Araneae, Zodariidae): eyes on the run, European Journal of Taxonomy 163 (163), pp. 1-24 : 3-4

Ballomma gen. nov.

urn:lsid:zoobank.org:act:CF0FE505-E714-4A09-8575-CFFC0 6C32C9A

Type species

Ballomma erasmus gen. et sp. nov.

Diagnosis

Ballomma gen. nov. is a member of the Cryptothelinae characterized by the eye position with touching ALE and AME, the shield-shaped sternum without or with tiny precoxal sclerites, the female palp with triangular flattened palpal tarsus, the male palp with concave tegulum accommodating the thin, slightly curved embolus directed diagonally over the tegulum and the epigyne with cul-de-sac ducts.

Etymology

The genus name is derived from the combined Greek terms βαλλω (= to touch) and ομμα (=eye), referring to the touching anterior lateral eyes. The gender is neuter.

Affinities

Ballomma gen. nov. clearly belongs to the Cryptothelinae, a subfamily of the Zodariidae that has been characterized by nomenclatorial problems: poor definitions and misplacements ( Jocqué 1991; Jocqué & Henrard 2015). It has the modified endites and an eye position of a type that only occurs in that subfamily. The present genus has some superficial resemblance with Capheris Simon, 1887 with which it shares the triangular female palpal tarsus and the closely set AME and ALE. However, in Ballomma gen. nov. the eyes are even more closely set and characters of sternum, carapace profile and structure of the genitalia are all different. As for the latter character there is a superficial resemblance with Aschema Jocqué, 1991 from Madagascar in which the ALE and AME are also very closely set. The shape of a number of undescribed Aschema species have somatic and genitalic characters that come close to those of the Ballomma gen. nov. species in the present article. However, the characteristics of the sternum and carapace and of the genitalia, and the modified leg IV, clearly separate them from the genus here described.

Description

HABITUS. Medium size to small spiders (4.5–7.5) with smooth teguments. Carapace longer than wide (L/W <1.4–1.6), without setae apart from a few longer hairs on clypeus; widest at level of coxae II–III, narrowed to about 0.43–0.66 times maximum width in eye region (cephalic width measured on posterior tangent of PME). Cervical grooves poorly indicated. Profile: flat; fovea in shallow depression.

COLOURATION. Carapace medium brown; chelicerae, legs, mouthparts and sternum medium to orange brown; abdomen dorsum with complex dark pattern on pale background; in some cases with four apodemes, sides grey, venter pale sometimes with dark pattern; in males sclerotized in front of epigastric fold and slightly sclerotized in front of spinnerets.

EYES. In three rows; ALE in front of AME and touching each other; AME close together sometimes touching; posterior row recurved, eyes apart. All eyes pale and subequal. Clypeus retreating, height 2.5 to 3.6 times diameter of AME, with some dispersed setae.

PROSOMA. Chilum double, sometimes poorly delimited, slightly more than twice as wide as high; no setae. Chelicerae conical with many evenly dispersed setae; fangs shorter than wide at base. Labium triangular, narrowed base. Endites roughly triangular, converging, with basolateral extension accommodating palpal coxae. Sternum shield-shaped, as wide as long or slightly longer than wide, without triangular extensions or precoxal sclerites; anterior margin straight, lateral margins slightly sinuous.

LEGS. Slender; formula 4123. Spination reduced on legs I and II, well developed on III and IV with spines numerous on T and Mt III and IV. Spines slender. With few or without hinged hairs.

FEMALE PALP. With tarsus triangular and flattened, with row of prolateral thorns, retrolaterally with some thin spines; palpal claw with some small teeth at base; turned inward over less than 35°; without distal patch of chemosensitive setae.

ABDOMEN. Oval; tracheal spiracle small, somewhat advanced. Females and juveniles with six spinnerets. Female ALS large, conical, biarticulate. PLS without, PMS with one cylindrical gland spigot. Colulus represented by field with few setae.

MALE PALP. Patella sometimes with swelling; RTA variable; cymbium with well developed basal flange and with group of truncated subapical thorns; subtegulum strongly developed, with transverse ridges; tegulum with prolateral concavity, distally with dorsal and ventral extensions; accommodating thin, slightly curved embolus, directed diagonally over tegulum. Epigyne simple, with internal structure characterized by cul-de-sac ducts, visible in transparency.

Distribution

Ballomma gen. nov. is so far only found in the mountain forests of the Limpopo Province in northern South Africa.