Shearella browni Shear 1978

Shearella browni Shear, 1978 comb. rest. Figures 17–19, 14 A−D, 20D, G. Monoblemma browni Shear, 1978: 23, figs. 57–61 (Male holotype from Périnet, Madagascar, III. 1969, W. L. Brown leg., deposited in AMNH, examined); Sankaran & Sebastian, 2016: 447 (Transferred from Shearella). Shearella browni: Lehtinen, 1981: 54 (complementary description of male holotype). Other material examined. MADAGASCAR. Andosibe, 1150m, (18°51'54.61"S, 48°27'24.44"E), Gary D. Alpert leg., 5.VII.1992, 1 ♂, 1 ♀ (MCZ-IZ 53665). Paratypes: same data as the holotype, 4 ♂ 5 ♀ (AMNH), 1 ♀ (AMNH, vchLAM-564); 10 km SW of Antalaha, Ambohitsara, 20m, (14°57'4.18"S, 50°13'59.88"E), Gary D. Alpert leg., 4.II.1989, 1 ♀ (MCZ-IZ 53667). Justification of the transfer. Sankaran and Sebastian (2016) transferred this species to Monoblemma, suggesting that it better fit the diagnostic features of that genus. However, the only distinguishing feature separating this species from others in Shearella is the poorly elevated ocular tubercle. In contrast, the genital morphology of both males and females, as described herein, along with the species’ geographical distribution, supports its reclassification within Shearella. Males of Shearella possess a filiform, very thin embolus inserted on a subrounded copulatory bulb. Additionally, the spermatic duct forms a subapical loop internally. Females exhibit simple, rounded receptacles without internal glands and a short central process. The height of the ocular tubercle is variable within the genus: both Shearella browni Shear, 1978, and Shearella lilawati Lehtinen, 1981, have a low ocular tubercle, yet all Shearella species share the aforementioned morphological characters. Diagnosis. Males of Shearella browni Shear, 1978 comb. rest. are very similar to those of Shearella alii Sankaran & Sebastian, 2016 and Shearella selvarani Lehtinen, 1981 by the very long embolus (Sankaran & Sebastian, 2016: 444, figs. 1A–B, 2A–F, 3A–D; Lehtinen, 1981: 53, figs. 204, 209, 213) but can be distinguished by the embolus almost as long as the copulatory bulb (Figs. 17G–J, 19A–B, 20D). Females are similar to those of Shearella lilawati Lehtinen, 1981 by the subrounded seminal receptacles, but can be distinguished by the smaller receptacles and thinner central process (Figs. 19D–E, 20G). Redescription. Male (based on holotype AMNH and complemented with a male MCZ-IZ 53665). Total body length 1.99, carapace length 0.90, width 0.76, height 0.58. Clypeus height 0.19. Eyes arranged in a compacted group: four eyes, ALE 0.08, PLE 0.04; PLE very close to each other. Sternum sub-trapezoidal, with recurved sides and straight posterior edge, length 0.56, width 0.77. Chelicerae (paturon) length 0.18. Legs: Leg I—femur 0.74/ patella 0.25/ tibia 0.57/ metatarsus 0.36/ tarsus 0.41/ total 2.35; II—0.56/ 0.23/ 0.47/ 0.29/ 0.28/ 1.86; III— 0.57/ 0.24/ 0.43/ 0.23/ 0.21/ 1.69; IV—0.76/ 0.20/ 0.69/ 0.45/ 0.38/ 2.48. Abdomen length 1.10, width 0.92. Body coloration light reddish-brown, carapace marginally darker with small marginal granules (Figs. 17A–F, 18A–D). Legs light brown, metatarsi and tarsi yellowish. Spinnerets light brown. Carapace: cephalothorax reticulate, with small granules on posterior side, sub oval-shaped, anterior edge projected; four eyes arranged in a compacted group, ocular tubercle low, ALE>PLE, ALE and PLE close to each other; clypeus very high and anteriorly projected with straight anterior edge (Figs. 17A–F, 18A–D); thoracic region reticulate, high, thoracic very short, transversal (Figs. 17A, 18A); Chelicerae with developed laminar, canaliculate frontal apophysis, anteriorly positioned (Figs. 17B, 18A, C); endites sub-quadrangular, anteriorly narrow and projected; labium wide with a median deep depression; sternum rugose almost as long as wide (Figs. 17C, 18C). Legs with fine setae, femora with granulated cuticle, tibiae-tarsi cuticle striated, tarsi slightly longer than metatarsi. Opisthosoma: with some white, fine setae on posterior edge (Figs. 17F, 18C); dorsal scutum oval-shaped, smooth; ventral scutum (pulmonar scutum) finely reticulated with straight posterior edge (Figs. 17F, 18C); with three lateral scuta, extending to the posterior side of the anal plate, lateral regions with some very small free sclerites (Figs. 17E, 18C); postgenital scutum narrow, rectangular, long; preanal scutum rectangular, approximately as wide as the pulmonar scutum, with straight lateral edges. Six spinnerets surrounded by the anal plate (Figs. 17F, 18C). Palp: femur cylindric, thin with several setae on the cuticle; patella very short with long setae; tibia swollen with simple and long setae; cymbium very short; bulb large, subrounded; spermatic ducts very wide at base, filiform towards embolus; embolus very long, almost as long as bulb (Figs. 17G–J, 19A–B, 20D). Female (MCZ-IZ 53665). Total body length 1.15, carapace length 0.53, width 0.46, height 0.38. Clypeus height 0.17. Eye diameters and interdistances: ALE 0.04, PLE 0.03; PLE and ALE close to each other. Sternum length 0.33, width 0.34. Chelicerae (paturon) length 0.20. Leg measurements: Leg I—femur 0.42/ patella 0.12/ tibia 0.24/ metatarsus 0.22/ tarsus 0.23/ total 1.24; II—0.36/ 0.14/ 0.25/ 0.21/ 0.20/ 1.17; III—0.27/ 0.14/ 0.22/ 0.18/ 0.15/ 0.98; IV—0.42/ 0.14/ 0.36/ 0.24/ 0.20/ 1.38. Abdomen length 0.81, width 0.64. Coloration as male, but paler, legs uniformly brown, paler, metatarsi and tarsi yellowish (Fig. 18 D−F). Carapace: cephalothorax rugous; eyes arranged in a compacted group ALE>PLE; clypeus high, anteriorly projected (Fig.18D); thoracic region rugous (Fig. 18D); Chelicerae with poorly developed frontal apophyses; endites subquadrangular-shaped with the wide basal edge, narrowing towards the distal edge (Fig. 5D); labium trapezoidal-shaped and wider that long (Fig. 18F); sternum rugose with few setae on margins (Fig. 18F. Opisthosoma: covered with white and black fine setae (Fig. 18F); scuta as in the male. Genitalia orifice small, placed at posterior edge of epigynal fold; central process very short; seminal receptacles small, membranous, rounded; vulval ducts short, thin (Figs. 19D–E, 20G). Distribution. Only known from Madagascar.