Indicoblemma cruxi, Lin & Li, 2010

Lin, Yucheng & Li, Shuqiang, 2010, New armored spiders of the family Tetrablemmidae from China, Zootaxa 2440 (1), pp. 18-32 : 19-21

Indicoblemma cruxi sp. nov.

Figs 1–8 , 50

Type material: Holotype: male ( IZCAS), Sanjiao Cave ( T.: 10 ºC; H.: 93%; Alt.: 1795 m), Jiuxiang Town, Yiliang County [25°08´N, 103°24´E, Yunnan, China], 8 April 2007, Y.C. Lin and J. Liu leg. Paratypes: 24 males and 37 females, same locality data as holotype, 15 August 2007, Y.C. Lin and Y.H. Guo leg. ( IZCAS) .

Etymology. The specific name is come from Latin crux = crossed, in reference to the modified projections at the anterior surface of male chelicerae.

Diagnosis. This new species is similar to Indicoblemma sheari Bourne, 1980 , but may be distinguished by 1) the crossed long apophyses of the anterior chelicerae, 2) the geniculation in the middle of pedipalpal femur, 3) the egg-shaped pedipalpal tibia, 4) the slit-opening of epigynal pit and5) the detailed differences of female vulva structure.

Description. Male: 1.18–1.26. Coloration saffron. Prosoma length 0.54–0.60, width 0.42–0.49, maximal height 0.50–0.56. Opisthosoma length 0.78–0.86, width 0.57–0.65. Eyes small, almost ovoid, subequal in size. Anterior eye row straight as viewed from above. PME absent. Ocular base black. Cephalic pars sleek, slightly upheaved. Dorsal shield of prosoma retiform, strongly rugose and denticules along the margins. Distal cheliceral tooth strong, without basal cheliceral boss. A pair of fingerlike apophyses crossed at chelicerae anteriorly ( Fig. 1 ). Sternum surface finely retiform, wrinkled along the margins, fused to dorsal shield of prosoma. Leg measurements: I 1.50 (0.48, 0.14, 0.34, 0.26, 0.28); II 1.32 (0.42, 0.12, 0.30, 0.22, 0.26); III 1.24 (0.38, 0.12, 0.26, 0.22, 0.26); IV 1.62 (0.48, 0.14, 0.40, 0.30, 0.30). Leg formula: 4-1-2-3. Femur, tibia, metatarsus of legs I–IV transversely striated. Of opisthosoma dorsal scutum long oval, modified tiny pits, ventral scutum with irregular veins. Lateral scutum I reaches the half of margin of pulmonary plate. One pair of perigenital plates. Postgenital plate covered the anterior brim of preanal plate.

Pedipalpal bulb pyriform, sharply extended at apex. Embolus relatively thin. Tip of embolus wedgeshaped. Palpal tibia ovoid, distally narrow and proximally wide, with a distal trichobothrium. Palpal femur curved and rugose at middle part of ventral surface ( Fig. 7 ).

Female: 1.32–1.40. Prosoma length 0.60–0.66, width 0.42–0.47, maximal height 0.57–0.62. Opisthosoma length 1.04–0.92, width 0.68–0.73. Ocular area not modified. Eyes pattern as in male. All eyes subequal in size. Chelicerae without projection. Leg measurements: I 1.46 (0.46, 0.14, 0.34, 0.24, 0.28); II 1.34 (0.40, 0.14, 0.30, 0.22, 0.28); III 1.22 (0.34, 0.12, 0.28, 0.22, 0.26); IV 1.64 (0.48, 0.14, 0.42, 0.30, 0.30). Leg formula: 4-1-2-3. PA with width about 2 times its length and 4/3 times postgenital plate width, laterally margin indistinctively contracted ( Fig. 5 ). Genital area, postgenital and preanal plate with plumose long setae.

Genital central process unclear at apex, with an obvious opening at base. Epigynal fold visible. Vulval duct membranous, inner vulval plate slightly sclerotized ( Fig. 6 ).

Natural history. The species occurs in dark cave and they usually live under small stones and rocks.

Distribution. Known only from the type locality ( Fig. 50 ).

Figures

FIGURE 50. Locality records of tetrablemmid species in China.

FIGURES 1–8. Indicoblemma cruxi sp. nov. 1 Male prosoma, dorsal view; 2 Female prosoma, ventral view; 3–4 Male left chelicera (3 lateral, 4 frontal view); 5 Female opisthosoma, ventral view; 6 Female genital area (KOH-treated), ventral view; 7– 8 Male left pedipalp (7 prolateral, 8 retrolateral view). Scales: 0.1 mm