Cybaeus adenes Chamberlin & Ivie 1932,

Bennett, Robb, Copley, Claudia & Copley, Darren, 2019, Cybaeus (Araneae: Cybaeidae): the adenes species group of the Californian clade, Zootaxa 4711 (2), pp. 245-274: 248-250

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Cybaeus adenes Chamberlin & Ivie 1932


Cybaeus adenes Chamberlin & Ivie 1932 

Figs 1–11View FIGURES 1–3View FIGURES 4–8View FIGURES 9–11, 59–60View FIGURES 56–60, 69View FIGURE 69

Cybaeus adenes Chamberlin & Ivie 1932: 24  , fig. 59 (in part, holotype only). Roewer 1954: 89. Bonnet 1956: 1300. Roth 1956: 178. Roth & Brown 1986: 3. Bennett 2006: 479, Figs 17–20View FIGURES 15–17View FIGURES 18–20. Copley et al. 2009: 372, fig. 5. World Spider Catalog 2019.

Cybaeus grizzlyi: Roth 1956: 178  . Roth & Brown 1986: 3.

Cybaeus adenoides: Roth 1956: 178  . Roth & Brown 1986: 3.

Type material. Holotype ♀. U.S.A.: California: Marin County, R. V. Chamberlin ( AMNH), examined but subsequently lost. Neotype ♂ designated by Bennett (2006) from U.S.A.: California: Marin County, San Geronimo (37°59'N 122°42'W), 19 September 1963, J. Ivie & W. Ivie ( AMNH), examined. See discussion of type material and synonymy in Bennett (2006).

Other material examined. Specimens and locality data in Bennett (2006). (Note: Green Valley locality, considered by Bennett (2006) to be “probably Sonoma Co.”, could be in Solano Co.)

Diagnosis. The male of C. adenes  is diagnosed by the morphology of the proximal arm of the tegular apophysis: tip bifid with the two tips slightly divergent ( Figs 1View FIGURES 1–3, 59–60View FIGURES 56–60). Known males of the other species of the adenes  group have either a single ( C. amicus  : Fig. 56View FIGURES 56–60; C. auburn  : Fig. 63View FIGURES 61–64; C. grizzlyi  : Fig. 61View FIGURES 61–64) or trifid ( C. reducens  : Fig. 57View FIGURES 56–60) tip on the proximal arm of the tegular apophysis. Males of some species also have a bifid tip of the proximal arm of the tegular apophysis but in those males there are fewer peg setae on the patellar apophysis and the bifid tips are more or less convergent ( C. sanbruno  : Figs 45View FIGURES 44–46, 67View FIGURES 65–68; C. schusteri  : Figs 51View FIGURES 50–53, 65View FIGURES 65–68).

The female of C. adenes  is distinguished from all other females of the adenes  group except C. grizzlyi  by the form of the atrium. The atrium in females of C. adenes  and C. grizzlyi  is inverted U-shaped or lyriform, relatively narrow (length from epigastric groove to anterior margin> width between lateral margins), and widest anteriorly ( C. adenes  : Figs 4, 7View FIGURES 4–8, 9View FIGURES 9–11; C. grizzlyi  : Fig. 30View FIGURES 28–30). The atrium in females of all other species of the adenes  group either has its lateral ends strongly curved anteriorly ( C. sanbruno  : Figs 47–48View FIGURES 47–49), is inverted U- or vase-shaped (but not lyriform) and widest posteriorly ( C. schusteri  : Fig. 53View FIGURES 50–53; C. amicus  : Figs 15–16View FIGURES 15–17; C. torosus  : Fig. 54View FIGURES 54–55; C. pearcei  : Fig. 33View FIGURES 33–34), or is relatively broad with length <width ( C. reducens  : Figs 38, 41, 43View FIGURES 38–43; C. auburn  : Figs 21–22View FIGURES 21–24). (Most females of C. schusteri  are distinguished by the inverted vase-shaped atrium ( Fig. 53View FIGURES 50–53) but the atrial morphology of some specimens may resemble that of females of C. adenes  and C. grizzlyi  . Collection of males with females may be the only way to ensure reliable identification in such instances.) Females of C. grizzlyi  and C. adenes  apparently are morphologically indistinguishable but can be separated by their respective distributions: both are found in the San Francisco Bay area of California but C. grizzlyi  appears to be restricted to Contra Costa and Alameda Counties to the east of San Francisco Bay ( Fig. 70View FIGURE 70) while C. adenes  is more widespread and found to the north and east of the Bay area in Marin, Napa, Sonoma, San Francisco, and possibly Solano Counties ( Fig. 69View FIGURE 69).

Description. Femora unbanded.

Male: (n=9). Patellar apophysis ( Fig. 2View FIGURES 1–3) with variable number of peg setae (most specimens have about two dozen) on concave or convex antero-dorsal surface. Very small retrolateral ridge anteriorly on tibia dorsal to carinate retrolateral tibial apophysis ( Fig. 3View FIGURES 1–3). Dorsal keel ( Figs 59–60View FIGURES 56–60) present on proximal arm of tegular apophysis, usually inconspicuous but occasionally prominent.

(n=8). CL 2.15–2.6 (2.5), CW 1.60–2.00 (1.83), SL 1.08–1.29 (1.22), SW 1.00–1.26 (1.17). Neotype CL 2.45, CW 1.80, SL 1.22, SW 1.17.

Female: (n=39). Atrium ( Figs 4, 7View FIGURES 4–8, 9View FIGURES 9–11) usually conspicuous, occasionally indistinct such that atrium may appear divided, anterior margin often sinuous, length of atrium (from epigastric groove to anterior margin) 1.5–2 times width (between lateral margins). Copulatory ducts ( Figs 5–6, 8View FIGURES 4–8, 10–11View FIGURES 9–11) well separated, attached to lateral margins of atrium.

(n=22). CL 1.58–2.8 (2.2±0.3), CW 1.12–1.90 (1.49±0.23), SL 0.86–1.35 (1.10±0.14), SW 0.79–1.28 (1.02±0.13). Holotype (lost) CL 2.20, CW 1.55, SL 1.12, SW 1.05.

Distribution and natural history. West central California: Marin, Napa, San Francisco, Sonoma, and possibly Solano Counties in the San Francisco Bay area ( Fig. 69View FIGURE 69). Males have been collected from mid-September to mid- November. Cybaeus adenes  and C. grizzlyi  are the most commonly encountered species of the adenes  group.


Departamento de Geologia, Universidad de Chile


Royal British Columbia Museum - Herbarium


American Museum of Natural History














Cybaeus adenes Chamberlin & Ivie 1932

Bennett, Robb, Copley, Claudia & Copley, Darren 2019

Cybaeus grizzlyi: Roth 1956: 178

Roth, V. D. & Brown, W. L. 1986: 3
Roth, V. D. 1956: 178

Cybaeus adenoides:

Roth, V. D. & Brown, W. L. 1986: 3
Roth, V. D. 1956: 178

Cybaeus adenes

Copley, C. R. & Bennett, R. & Perlman, S. J. 2009: 372
Bennett, R. G. 2006: 479
Roth, V. D. & Brown, W. L. 1986: 3
Bonnet, P. 1956: 1300
Roth, V. D. 1956: 178
Roewer, C. F. 1954: 89
Chamberlin, R. V. & Ivie, W. 1932: 24