Trisaria rex, Shear, 2020

Trisaria rex View in CoL , new species

Figs. 15–28 View FIGURES 15–19 View FIGURES 20–25 View FIGURES 26–31

Types: Male holotype and 3 female paratypes from. I-90 exit #37, 1300’ asl, N47°26.613’, W121°40.061’, 21 January 2005, W. Leonard, King Co., Washington, 25 February 2004, W. Leonard, C. Richart, deposited in Burke Memorial Museum, University of Washington , Seattle, Washington.

Etymology: The species epithet (Latin, “king”) refers to King County, Washington, to which the species seems endemic.

Diagnosis: Distinct in the form of the gonopods and ninth legs. The posterior branch of the median angiocoxite is very long ( mac2, Figs. 22 View FIGURES 20–25 , 27 View FIGURES 26–31 ), while it is short in both T. olympia and T. washingtonensis . In contrast to the robust form of the ninth leg telopodite in the other two species, that of T. rex is strongly compressed ( t9, Figs. 20, 23 View FIGURES 20–25 , 28 View FIGURES 26–31 ).

Description: Male from Twin Falls/Iron Horse trailhead. Length, 8.0 mm, width, 0.82 mm. Body form and secondary sexual modifications as described for genus. Gonopods ( Figs.20–22 View FIGURES 20–25 , 26, 27 View FIGURES 26–31 ) robust, sternum ( gst, Figs. 20, 21 View FIGURES 20–25 ) broad, well-sclerotized. Median angiocoxite ( mac, Fig. 20 View FIGURES 20–25 ) with two branches: the anteriormost ( mac1, Figs. 21 View FIGURES 20–25 , 26 View FIGURES 26–31 ) short, blunt; the posterior most ( mac2, Figs. 22 View FIGURES 20–25 , 26, 27 View FIGURES 26–31 ) long, bent posteriorly at nearly a right angle, then dorsally at a slightly more obtuse angle. Lateral angiocoxite ( lac, Fig. 20 View FIGURES 20–25 ) with three branches: the anteriormost ( lac1, Figs. 21 View FIGURES 20–25 , 26, 27 View FIGURES 26–31 ) long, slightly curved, divided at tip into two processes, each of these further divided into three or four smaller, acute terminations, one set pointing anterior, the other posterior. Median branch ( lac2, Figs. 21, 22 View FIGURES 20–25 , 26, 27 View FIGURES 26–31 ) set with dense array of fine spines, giving comb-like appearance. Posteriormost branch ( lac3, Figs. 22 View FIGURES 20–25 , 27 View FIGURES 26–31 ) short, simple, bluntly acuminate. Colpocoxites ( cc, Figs. 22 View FIGURES 20–25 , 26, 27 View FIGURES 26–31 ) entirely membranous, with scaly cuticle. Ninth legs ( Figs. 23 View FIGURES 20–25 ) much reduced, sternum ( st9, Figs. 23 View FIGURES 20–25 ), coxae ( c9), telopodites ( t9) almost completely fused, telopodites much flattened, distally setose; coxae with minute anterior pore ( cp, Fig. 23 View FIGURES 20–25 ). Tenth legs ( Fig. 24 View FIGURES 20–25 ) with enlarged coxae ( c10, Fig. 24 View FIGURES 20–25 ) bearing glands ( gp, Fig. 24 View FIGURES 20–25 ).

Female from Twin Falls/Iron Horse trailhead. Length, 9.2 mm, width 0.90 mm. Nonsexual characters as in male.

Distribution: WASHINGTON: King Co.: North of I90, Pratt Lake Trailhead, N47°23.829, W121°29.109, 25 October 2003, W. Leonard, m, f. Same, but N47°23.821’, W121°29.108’, 1700’ asl, 15 October 2009, mm. I-90 at Snoqualmie River, Twin Falls/Iron Horse Trailhead, N47°26.651’, W121°40.081’, 25 February 2004, W. Leonard, C. Richart, m, f; Tokul Creek, 520’ asl, 47.556°N, 121.817°W, 21 November 1979, R. Crawford, m.

Notes: Presently this species is known only from central and western King County, Washington.