Rhepoxynius J. L. Barnard 1979

Paraphoxus vigitegus

DIAGNOSIS.—Body of broad form; rostrum from dorsal view abruptly narrower than head, rostrum very narrow and short for genus; eyes vestigial in female, composed of 7–9 weakly aggregated ommatidia, very large in male, the color of eosin in alcohol, ocular ganglia very prominent in both sexes (solid black in figures); epistome strongly produced forward in a thin, acute, dorsally curled, and reverted cusp; gland cone of antenna 2 strongly developed; palp article 4 of maxilliped apically simple; gnathopods 1 and 2 with article 5 longer than 6, latter narrow on gnathopod 1, slightly stouter on gnathopod 2, palm transverse; ratios of articles 5–6 on gnathopod 1, 69: 45, on gnathopod 2, 64: 45. Pereopod 3: article 4 scarcely wider than article 2, both very stout, article 5 nearly as stout as 4, article 6 narrow and shorter than 5, ratio of widths of articles 2, 4, 5, 6 = 32 : 33 : 31 : 8; article 2 with large posteroproximal tooth. Pereopod 4: ratio of widths of articles 2, 4, 5, 6 = 43 : 26 : 18 : 7. Pereopod 5: article 2 slightly longer than broad, posteroventral margin truncate, slightly oblique, sweep point slightly exceeding distal end of article 4, posterior margin bearing 4–6 medium-size serrations resembling castellations. Uropods 1–2 stout, uropod 2 much smaller than 1, spines of peduncles short and stout and sharp, rami naked in females and juveniles, inner ramus with one marginal spine in adult male. Uropod 3 of female with very short inner ramus, about 30 percent as long as outer ramus, article 2 of outer ramus about one-seventh as long as article 1; male uropod 3 with subequal strongly setose rami. Telson slender, apices sinuously truncate, with 2–3 subterminal lateral notches and 1 or 2 short or long setae in each notch. Pleonal epimeron 3 with convex posterior margin in male, flat in female, posteroventral corner grossly rounded but with weak incisions, strongly setose; urosome large in female, small in male, urosomites 1–2 immovably coalesced, marked laterally with strong ridge lines differing in male and female (see figures), dorsal surface of presumed urosomite 2 with enormous, anteriorly reverted tooth, larger in female than in male.

HOLOTYPE.—USNM 127121, female, 4.6 mm.

TYPE-LOCALITY.—Station 1, 44°39.8′N, 124°59.0′W, 30 m, 20 June 1962.

MATERIAL.—Twenty-three specimens from the type-locality.

RELATIONSHIP.—The development of a dorsal cusp on the urosomites is highly unusual in Paraphoxus, for only P. cornutus (Schellenberg, 1931), has been reported to have a large reverted dorsal cusp on urosomite 3. The coalescence of urosomites 1–2 is also of strong concern because it usually has familial or generic significance. In the present case, however, there is no other significant difference of the species from its congeners and there are strong resemblances to P. fatigans and other species of the genus.

Of its allopatric congeners, Paraphoxus vigitegus, new species, most resembles P. fatigans J. L. Barnard (1960b), mainly because of the shape of the head, the presence of an epistomal cusp, the conditions of gnathopods 1–2, pereopods 3–5, uropods, telson, and pleonal epimera. Besides the urosomal differences, P. vigitegus differs from P. fatigans by the curled condition of the epistomal cusp and the larger gland cone.

Paraphoxus vigitegus also has affinities with P. abronius J. L. Barnard (1960b) but differs by the curled epistomal cusp, the narrower hands of the gnathopods, the longer gland cone, a strongly distinct pereopod 5, strongly spinose uropods 1–2, and much smaller female eyes. Paraphoxus daboius J. L. Barnard (1960b) has very weak female eyes but differs from P. vigitegus by the broader gnathopodal hands, broader rostrum, uncurled epistomal process, and the presence of a normal urosome.

DISTRIBUTION.—Oregon, 30 m.