Psilochorus papago Gertsch & Davis, 1942

Slowik, Jozef, 2009, A review of the cellar spider genus Psilochorus Simon 1893 in America north of Mexico (Araneae: Pholcidae), Zootaxa 2144, pp. 1-53 : 31-33

Psilochorus papago Gertsch & Davis, 1942

Figs. 108–117, 193

Types. Ψ holotype, two Ψ paratypes from 27 miles south of Nogales Arizona, USA, in Sonora Mexico; coll: A M & L I Davis, 15-Jun-1939. AMNH. Not examined. ɗ allotype and ɗ and Ψ paratypes from Canada del Oro, Santa Catalina Mountians (32.32 N, 111.06 W), Pima County, Arizona USA; coll: P Steckler, Aug-1937. AMNH. Examined.

PLATE 14. Figures 108–117. Psilochorus papago Gertsch and Davis. 108–113. Male. 108. Dorsal view of chelicerae. 109. Lateral view of chelicera. 110–111. Dorsal view of bulb apophysis. 112–113. Lateral view of procursus. 114–117. Epigynum. 114. Anterior view. 115. Ventral view. 116. Posterior view. 117. Lateral view.

Specimens examined. 7 ɗ, 6 Ψ; USA, Arizona, Pima County, 2 ɗ, Tucson Mountains, D B Richman, 08- Nov-1969, DPI; 2 ɗ, Pima County, 08-Nov-1969, DPI; Santa Cruz County, 1 Ψ, Nogales, Chamberlin R V, 04-Apr-1921, CAS; 1 ɗ 1 Ψ, Yank's Spring, Sycamore, Tamacacori Mtns, 03-Aug-1932, AMNH; 1 Ψ, Patagonia Mtns, O Bryant, 36–25, no date, AMNH; California, Los Angeles County, 1 ɗ, Lancaster, 19-Mar- 2005, NHMLA; 1 Ψ, Woodland Hills, D Boe, 01-Aug-1981, EM; Riverside County, 1 Ψ, Rubidoux, on horse ranch, in plastic termite trap, R Vetter, 22-Jan-2007, EM; San Bernardino County, 1 Ψ, Joshua Tree N M, 1.8 Mi S 29, Palms Ranger Station, 09-Mar-1969, CAS.

Diagnosis. Specimens may be distinguished by: male spur truncated with the ends of the spur being shaded as to appear as if the spur has a barb (Fig. 108), procursus end slit with the ventral side of the slit extending beyond and curving toward the ventral side (Figs. 112, 113), MEP of the epigynum has two low ridges close together (Fig. 116), and a wide PEP projection (Fig. 115).

Male: (N=5) Total length: 2.54 ± 0.20; carapace length: 1.06 ± 0.12; carapace width: 1.04 ± 0.08; leg 1: 18.35 ± 3.03 (5.12 ± 0.71 + 0.36 ± 0.06 + 5.41 ± 0.81 + 6.34 ± 1.46 + 1.11 ± 0.06); tibia 2: 3.39± 0.37; tibia 3: 2.62 ± 0.20; tibia 4: 3.55 ± 0.33. 19–20 leg I tarsal segments; femur1/carapace length: 4.83 ± 0.56; RT at 11.3–14.5%; DT at 5.2–10.8%. Color typical for the genus. Spur large, originating from the proximal portion of the chelicerae (Fig. 109), slightly curved in dorsal view, end truncate, shaded area of spur creates the appearance of a barb on the mesal surface in dorsal view (Fig. 108). Procursus thick, distal area slightly larger than stalk, spilt, dorsal end extending beyond ventral end and curving ventrally, end truncate or rounded (Figs. 112, 113). Bulb apophysis roughly triangular, directed slightly prolaterally, end rounded or weakly pointed, retrolateral tab low, extending to mid-length of the bulb apophysis (Figs. 110, 111).

Female: (N=5) Total length: 2.46 ± 0.47; carapace length: 0.97 ± 0.07; carapace width: 0.97± 0.03; leg 1: 13.90 ± 0.71 (3.81 ± 0.16 + 0.36 ± 0.04 + 4.10± 0.23 + 4.59 ± 0.28 + 1.04 ± 0.06); tibia 2: 2.60 ± 0.22; tibia 3: 2.10± 0.17; tibia 4: 2.87 ± 0.24. 19–20 leg I tarsal segments; femur1/carapace length: 3.93 ± 0.31; RT at 10.7–16.6%; DT at 7.1–10.1%. Color typical for the genus. No AEP. MEP with two adjacent mesal ridges (Fig. 114). Ridges very thin in ventral and lateral views (Figs. 115, 117). PEP rounded, dmPEP large, divergent, directed at the MEP ridges (Fig. 116).

Remarks. The barb appearance on the spur and the slit procursus with the longer dorsal side separates this species from all other male species with truncated spurs. The low MEP ridges and wide PEP projection on the epigynum will separate it from all other females.

Distribution. Southern California, Arizona, Western New Mexico into Mexico.