Cybaeus torosus Bennett spec. nov.

Figs 54–55, 71

Type material. Holotype ♀. U.S.A.: California: Alameda County [no other locality data], 22 March 1941, W.M. Pearce (AMNH).

Paratypes. U.S.A.: California: Alameda. 3♀, same data as holotype .

Etymology. The specific name is from the Latin for “muscular, bulging” and refers to the resemblance of the vulva of this species in dorsal view to a muscle-flexing body-builder.

Diagnosis. The male is unknown.

The female of C. torosus is unlikely to be confused with females of other adenes group species and is distinguished by a combination of features of the atrium and the copulatory ducts. The atrium is inverted, U-shaped, and widest posteriorly (Fig. 54). The outer lateral margins of the copulatory ducts are clearly visible through the integument in ventral uncleared view of the epigynum (Fig. 54) and the ducts themselves are broad and lightly sclerotized anteriorly at their origin at the atrium and narrowed and heavily sclerotized closer to the spermathecal heads (Fig. 55).

Description. Abdomen very dark; femora lightly banded.

Female: (n=4). Length of atrium (from epigastric groove to anterior margin) about twice width (between lateral margins) (Fig. 55).

(n=4). CL 2.6–3.0 (2.9), CW 1.70–2.10 (1.93), SL 1.24–1.43 (1.35), SW 1.12–1.30 (1.25). Holotype CL 2.9, CW 1.93, SL 1.35, SW 1.29.

Distribution. Known only from the type locality in Alameda County on the east side of San Francisco Bay in west central California (Fig. 71).