(Fig. 57B–D, Pl. 15A)
Scleroplax granulata Rathbun, 1893: 251; 1904: 188, pl. 7, fig. 5; 1917: 171, pl. 37, figs. 1–3, text fig. 109. — Weymouth 1910: 59, text fig. 85. — Schmitt 1921: 267, pl. 44, figs. 1–3. — Johnson & Snook 1921: 394. — Schmitt et al. 1973: 96. — Garth & Abbott 1980: 618, fig. 25.41. — Hart 1982: 228, fig. 94. — Ricketts et al. 1985: 384, fig. 300. — Jensen 1995: 30, fig. 40. — Campos-Gonzalez 2006: 33, fig. 1 A–C; 2007: 644, pl. 322 D2.
Diagnosis. Carapace subpentagonal, hard, granulate anteriorly near margins; punctate elsewhere; front narrow, produced, slightly convex. Orbits nearly circular, eyestalk short, thick. Antennules almost transverse. Chela of male swollen, heavy; those of female not as large. Dactyl curved, fixed finger with large tooth, fingers gaping. Pereopods 2–5 slender, granulate. Pereopod 4 longest, its segments narrow, flattened; dactyls slender, almost straight, nearly as long as dactyls. Male abdomen narrow, tapering gradually to broad terminal segment, female abdomen fringed with setae. Male carapace length about 3 mm, female to 6 mm.
Color in life. Grayish white, brownish, yellowish mottled with red-brown (Hart 1982).
Habitat and depth. Bays and harbors, symbiotic with echiuroid worm Urechis caupo, ghost shrimps Neotrypaea californiensis, N. gigas, Upogebia pugettensis, and U. macginitieorum; intertidal zone to 13 m.
Range. Roller Bay, Vancouver I. to El Coyote Estuary, Abreojos Point, Baja California; off Mazatlán, Sinaloa, Mexico. Type locality Ensenada, Baja California.