Cybaeus pearcei Bennett, 2019

Bennett, Robb, Copley, Claudia & Copley, Darren, 2019, Cybaeus (Araneae: Cybaeidae): the adenes species group of the Californian clade, Zootaxa 4711 (2), pp. 245-274 : 256-259

Cybaeus pearcei Bennett spec. nov.

Figs 33–34 , 71

Type material. Holotype ♀. U.S.A.: California: Alameda County, Calaveras Dam , 15 March 1939, W.M. Pearce ( AMNH).

Etymology. The specific epithet is a patronym honoring W.M. Pearce, the collector of the only known specimen of this species.

Diagnosis. The female of C. pearcei is characterized by its small atrium ( Figs 33–34 ): strongly concave and inverted U–shaped with inconspicuous relatively narrowly separated parallel lateral margins and length (from epigastric groove to anterior margin) 2.5–3.0 times width (between lateral margins). Other females of the adenes group that possess strongly concave inverted atria have the margins farther apart and not usually parallel and length to width ratios of 1.2–2.0 ( C. adenes : Figs 4 , 9 ; C. amicus : Figs 15–16 ; C. grizzlyi : Fig. 30 ; C. sanbruno : Figs 47–48 ; C. schusteri : Fig. 53 ; C. torosus : Fig. 54 ). The male is unknown.

Description. Femora unbanded.

Female: (n=1). Copulatory ducts ( Fig. 34 ) attached to anterolateral margins of atrium, nearly contiguous anteriorly; Bennett’s glands small and inconspicuous although possibly the specimen is newly matured and the glands are not fully developed (see Bennett 2006).

Holotype CL 2.00, CW 1.38, SL 1.03, SW 0.98.

Distribution. Known only from the type locality near the southern boundary of Alameda County in west central California ( Fig. 71 ).

Figures

FIGURE 71. Distributions of Cybaeus pearcei spec. nov. (●), C. torosus spec. nov. (). CA—California, OR—Oregon, NV—Nevada.

FIGURES 33–34. Cybaeus pearcei spec. nov., female holotype, copulatory organ (33 epigynum, ventral; 34 vulva, dorsal). CD—copulatory duct, HS—head of spermatheca. Scale bar: 0.1 mm.

FIGURES 4–8. Cybaeus adenes, females (4–6 holotype; 7–8 from San Geronimo, California), copulatory organ (4 epigynum, ventral; 5 vulva, ventral; 6 same, dorsal; 7 atrium, ventral; 8 vulva, dorsal). AT—atrium, BG—Bennett’s gland, BS—base of spermatheca, CD—copulatory duct, HS—head of spermatheca, SS—stalk of spermatheca. Scale bars: 0.1 mm.

FIGURES 9–11. Cybaeus adenes, females from vicinity of St. Helena, California, copulatory organ (9 epigynum, ventral; 10 vulva, ventral; 10 same, dorsal). Scale bars: 0.1 mm.

FIGURES 15–17. Cybaeus amicus, females (15 from Stanford University, California; 16–17 from Holy City, California), copulatory organ (15 epigynum, ventral; 16 vulva, ventral; 17 same, dorsal). CD—copulatory duct. Scale bars: 0.1 mm.

FIGURES 28–30. Cybaeus grizzlyi, females (28 from hills above Berkeley, California; 29 lectotype of C. adenoides; 30 from Orinda, California), copulatory organ (28 teneral vulva, dorsal; 29 vulva, dorsal; 30 atria, ventral). CD—copulatory duct, HS—head of spermatheca. Scale bar: 0.1 mm.

FIGURES 47–49. Cybaeus sanbruno, females from San Bruno Mountain, California, copulatory organ (47 epigynum, ventral; 48 vulva, ventral; 49 same, dorsal). Scale bars: 0.1 mm.

FIGURES 50–53. Cybaeus schusteri spec. nov. (50–52 male holotype, left palpus; 53 female from south of Monticello, California), copulatory organ (50 genital bulb, ventral; 51 patella and tibia, dorsal; 52 patella and tibia, retrolateral; 53 vulva, ventral). DK—dorsal keel of proximal arm of tegular apophysis, RR—retrolateral ridge dorsal to retrolateral tibial apophysis. Scale bars: 0.1 mm.

FIGURES 54–55. Cybaeus torosus spec. nov., female holotype, copulatory organ (54 epigynum, ventral; 55 vulva, dorsal). Scale bars: 0.1 mm.