Type Material

 

            Holotype: “Datames striatus: Female holotype from Camp Grant, Arizona, USA (BNHM). Datames cinerea: Type locality of male holotype unknown (Academy of Natural Sciences, Philadelphia, Pennsylvania, USA). We did not examine the female holotype” (Cushing et al., 2018, p. 459).

 

            Measurements: “Males (n = 8). TL 31.0–50.0; CL 9.0–16.0; CH 3.4–5.6; FNL 0.3–2.0; FNH 0.4–0.9; FFH 1.0–1.6; PL 25.0–40.5; PT 7.0–8.0; PMT 1.7–3.0; LI 20.5–31.0; LIV 27.0–43.0; PPL 5.0–7.9; A/CP 4.3–5.6; FNL/FNH 0.5–2.5; FFH/FNH 1.3–2.3; FFH/CH 0.2–0.5” (Cushing et al., 2018, p. 459).

“Females (n = 2). TL 34.5, 50.0; CL 9.0, 17.5; CH 4.0, 5.5; PL 22.0, 35.0; PT 7.5, 7.7; PMT 2.0, 2.9; LI 19.5, 26.0; LIV 34.5, 35.0; PPL 3.9, 4.0; A/CP 3.9, 4.0” (Cushing et al., 2018, p. 459).

 

            Operculum Description: “Muma’s illustration is accurate (1951, fig. 31, p. 46). Thin anterior arms; relatively large posterior wings (Fig. 4E)” (Cushing et al., 2018, p. 460).

            

            Chelicerae Description: “Male. VDC apical, oriented prolaterally, narrow, with thin carina (Fig. 1F, arrow). Fixed finger broad at the base narrowing at the apical third of the length in retrolateral view with no median dentition. Movable finger: prominent MP-two tiny MSM (some specimens with just one)-either a very small, but distinct, MM or just a slight ridge at that location (difficult to see in Fig. 2S)-a long ridge-like MD; distinct MPL (Figs. 2S & T). Fondal notch seemingly curved and distinct (Figs. 2S & T). Two tiny RFA; fondal teeth graded I, III, II, IV retrolaterally and I, II, III, IV prolaterally (Fig. 3F)” (Cushing et al., 2018, p. 460).

“Female. Fixed finger: large FP-2 small FSM-FM-2 small FSD-smaller FD. Movable finger: large MP-two small MSM-medium MM; smaller but distinct MPL (Figs. 2U & V). Two RFA, proximal tiny; fondal teeth graded as in the male” (Cushing et al., 2018, p. 460). 

 

Diagnosis: “The shape of the male chelicera with its slightly rounded fondal notch, a tiny MM, and a flattened ridge-like MD distinguishes this species from all other Eremocosta. Only E. gigasella has a ridge-like structure positionally homologous to the sharper distal ridge that might be a modified MD (see Figs. 2S & O, arrows). Eremocosta gigashas a distinctive MD tooth at that same position on the movable finger (Fig. 2K, arrow). The genital operculum of E. striata is most similar to that of E. calexicensis; however, the curved distal portions of the genital wings are more rounded than those of E. calexicensis (compare Figs. 4E & B)” (Cushing et al., 2018, p. 459). 

 

Other Information: “Eremocosta striata is a large species that can be seen by vehicle headlights scurrying across a road (pers. obs, JB). It seems to occupy the Sonoran region east of the Colorado River in Arizona and the state of Sonora, México” (Cushing et al., 2018, p. 460).