Polyonyx quadriungulatus Glassell, 1935

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 159-160

Polyonyx quadriungulatus Glassell, 1935

( Fig. 37F)

Polyonyx quadriungulatus Glassell, 1935: 93 , pl. 9. — Haig 1956: 80; 1960: 236, pl. 41, fig. 2; text fig. 12 (1). — Haig et al. 1970: 26. — Kudenov & Haig 1974: 105. — Jensen 1995: 76, fig. 154.

Diagnosis. Front convex or concave in dorsal view, with short fringe of setae. Carapace subovate, 1.2 –1.4 times as broad as long. Chelipeds unequal. Merus with broad, rounded lobe on anterior margin; posterior margin fringed with fine setae. Carpus with anterior margin bearing high lamellar crest, anterior, posterior margins fringed with setae. Chela slender, dorsal surface swollen, without crest in major cheliped; outer margin with sharp crest lined with row of granules, thick fringe of setae extending nearly to apex of dactyl, gape of fingers with scattered short setae. In major chela, dactyl crosses over fixed finger at apex of chela. Pereopods 2–4 smooth, all segments with fringe of fine setae. Merus with fringe of fine setae. Propodus with pair of movable spinules at distal end of posterior margin, single movable spine posterior to them, one on middle or proximal third of posterior margin. Dactyl with 4 fixed spines, distal three large, proximal one small. Telson with 7 plates. Carapace length to 13.5 mm.

Color in life. Carapace, chelipeds dark brown, mottled with green, red; pereopods 2–4 lighter, banded ( Glassell 1935).

Habitat and depth. Strictly symbiotic, living in pairs within tubes of polychaete Chaetopterus variopedatus (Renier, 1804) , intertidal zone to 46 m.

Range. Santa Rosa I., California to Punta San Eugenio, Baja California, Mexico , Gulf of California at Puerto Peñasco, Loreto, and El Mogote. Type locality Estero de Punta Banda, Baja California, Mexico .