Hourstonius baciroa (J. L. Barnard 1979)

Gitanopsis baciroa

DIAGNOSIS OF FEMALE.—Pleonites dorsally smooth. Eyes large, formed of dark core surrounded by unpigmented ommatidia (in alcohol). Gnathopod 1 large, similar in structure to gnathopod 2, subchelate, process of article 5 reaching about three-fourths along posterior margin of article 6; gnathopod 2 larger than gnathopod 1, posterodistal end of article 2 with slender seta, article 6 with 2 anterior thin spines laterally, process of article 5 reaching fully along posterior margin of article 6. Telson much shorter than peduncle of uropod 3. Coxa 1 more or less quadrate, coxa 2 rounded ventrally.

MALE.—Body size much smaller than female, ranging between 1.50 and 1.75 mm in length, females of similar size with small eye, males with eye relatively as large as that of ovigerous females longer than 2.50 mm, males with juvenile-like conditions of sparser spination and less expanded hand of gnathopod 2.

ILLUSTRATIONS.—Following mouthparts magnified identically: mandible, lower lip, maxillae 1–2, maxilliped; coxae 3–4 reduced in magnification in comparison with coxae 1–2; pereopod 2 similar to pereopod 1; apices of pereopods 3–5 missing on material; detached telson and uropod 3 magnified to same degree.

HOLOTYPE.—USNM 169028, female “n,” 2.77 mm (illus.).

TYPE-LOCALITY.—DAW 8, Galapagos Islands, Isla Santa Cruz, off Academy Bay on Isla Coamaño, 13 February 1962, wash of Cystophora (depth unknown).

VOUCHER MATERIAL.—Type-locality, female “v,” 2.89 mm (illus.).

RELATIONSHIP.—This species scarcely differs from Gitanopsis vilordes J. L. Barnard (1962c) but consistently bears a thin posterodistal seta on article 2 of gnathopod 2, instead of a stout spine, and has a much different shaped coxa 2, being narrow and apically rounded rather than subquadrate.

MATERIAL.—SCO 19; TOP 3; GAL 116, ?120; DAW 3, 8, 19.

DISTRIBUTION.—Gulf of California at Puerto Peñasco and Topolobampo, 0–1 m; Galapagos Islands, intertidal.