Pholcus gracillimus Thorell, 1890

Yao, Zhiyuan, Tavano, Maria & Li, Shuqiang, 2013, Notes on four pholcid spiders (Araneae: Pholcidae) described by T. Thorell from Southeast Asia, Zootaxa 3609 (3), pp. 302-310 : 303-305

Pholcus gracillimus Thorell, 1890

Fig. 3

Pholcus gracillimus Thorell 1890: 298 . Workman 1896: pl. 71, figs a–g. Simon 1905: 55. Huber 2011: 283, figs 1360, 1394–1395 and 1420–1424 (misidentification).

Type material examined. Holotype: Male (MSNG), Sungei Bulu, Sumatra, Indonesia, September 1878, O. Beccari leg.

Diagnosis. The species resembles P. fragillimus Strand, 1907 , but can be distinguished by details of pedipalpal morphology ( Figs 3 A–D; absence of dorsal elongations on tarsus, different shapes of procursus and appendix).

Redescription. Male (holotype): Total length 4.68 (4.87 with clypeus), prosoma 1.01 long, 1.05 wide, opisthosoma 3.67 long, 0.71 wide. Leg I lost, leg II: – (6.60 + 0.51 + 5.77 + – + –), leg III: 15.90 (4.81 + 0.45 + 3.78 + 5.77 + 1.09), leg IV: 23.19 (6.54 + 0.50 + 5.32 + 8.27 + 2.56). Dorsal shield of prosoma, ocular area, clypeus, legs and opisthosoma yellowish, but marks beyond recognition; sternum brown. Opisthosoma with a brown, median stripe ventrally. Distance PME-PME 0.18; diameter PME 0.17; distance PME-ALE 0.02; distance AME-AME 0.06; diameter AME 0.07. Ocular area elevated; each eye triad on top of a relatively shorter eye-stalk directed towards laterally. No thoracic furrow. Sternum wider than long (0.69/0.63). Chelicerae with pair of black apophyses distally provided with two modified hairs each, pair of unsclerotized thumb-shaped apophyses proximolaterally, and two pairs of frontal apophyses. Pedipalpi as in Figs 3 A–B; trochanter with a long retrolateroventral apophysis; femur with a dorsal apophysis retrolaterally; procursus simple proximally but complex distally, with membranous and sclerotized elements and a long, dorsal spine; uncus with a scaly edge; appendix bent, with a branch medially and scales distally; embolus weakly sclerotized, with some transparent projections. Leg hairs lost. Distribution. Indonesia (Sumatra).

Remarks. The procursus, uncus and appendix of Huber’s (2011) P. gracillimus strikingly differ from those of the MSNG holotype. Thus, we consider Huber’s P. gracillimus a misidentification. Future work may confirm that Huber’s P. gracillimus is a new species. In addition, the MSNG holotype is extremely similar to P. kohi Huber, 2011 in having two pairs of frontal apophyses on the male chelicerae, a dorsal apophysis on the pedipalpal femur, and similar shapes of procursus, uncus and appendix, and the locality of the MSNG holotype is within the range of the latter. We have not seen the type specimens of P. k o h i, but we consider P. kohi dubious.

Figures

FIGURE 3. Pholcus gracillimus Thorell, 1890, based on male holotype. A – B. Right pedipalpus (A, retrolateral view; B, prolateral view); C. Bulbal apophyses, prolateral view; D. Distal part of right procursus, prolateral view.