Wallametopa cabon J. L. Barnard 1974

Wallametopa cabon

DESCRIPTION.—Rostrum sharp, lateral cephalic lobe apically truncate, slightly narrowed, midceplialic keel conical but apically blunt, epistome not reaching apex of keel, sharply delimited; eye large, antenna 1 about two-thirds as long as body, antenna 2 about half as long as body, occasionally longer; accessory flagellum minute, largely hidden under chitinous edge of article 3 of antenna 1; lobes of upper lip nearly equal to each other; spines of mandibles sparse; fused inner lobes of lower lip nearly cuboid, outer lobes tall and broad; inner plate of maxilla 1 naked, outer plate with six spines, apex of palm serrate and spinose, with strong subapical row of blunt setae; maxilla 2 with short plates, outer broad and subtruncate, inner subconical and shorter than outer; inner plates of maxilliped freely separate as in Stenothoe allinga (q.v.), outer plates slightly sharper than in S. allinga (see Figure 82OS), palp article 4 elongate, article 3 poorly spinose; coxa 2 rounded-trapezoidal apically, coxa 3 in male rounded apically and slightly tapered, rectangular and truncate in female, coxa 4 very broad (anteroposterior) in male, extended anteroventrally, narrower and unextended in female; stridulation ridges present on male coxa 4 and on female coxa 3 (female with 3 ridges); article 4 of gnathopod 1 short and weakly bulbous posterodistally, article 5 elongate and strongly setose postero-proximally, article 6 narrow, lacking palm, dactyl thick, stubby, apical bifidation bearing spine: gnathopod 2 enlarged, similar between the sexes, hand large, ovate, palm occupying most of posterior margin, toothed, defined by one marginal spine and one submarginal spine on medial face (one female with pair of spines in each position = aberration), dactyl fitting palm, setose on inner edge; pereopod 2 slightly smaller than pereopod 1 but not structurally distinct, posterior margins of articles 5–6 heavily spinose, locking spines of all pereopods in pairs, each member broadened towards apex, submembranous, edge of spine on medial side of pereopod presented sideways, dactyls with weak inner declivities, small apical spinule nearly fused with dactyl, no internal notches, no setae; article 4 of pereopods 3–5 not widely expanded, posterodistal process extending halfway along article 5 in pereopod 3, nearly fully in pereopods 4–5 (see Figure 83rP4, aberrant pereopod 4 with short process); epimera as illustrated; outer ramus of uropod 2 shorter than inner, bearing only one marginal spine; uropod 3 thin and elongate, article 2 of ramus half as long as peduncle, article 1 of ramus slighdy shorter than half, peduncle with five or six marginal spines, pair of spines transverse apically, formula generally four single marginal spines and terminal pair (one of which counted as marginal), article 1 of peduncle with pair of terminal spines; telson with three lateral spines on each side and one mediodorsal spine (unusual but consistent); cuticle with sparse setules, mainly on coxa 4.

ILLUSTRATIONS.—Uropod 3 drawn from dorsal side, spines pointing upwards towards observer; flagellum of antenna 1 with 12 articles, of antenna 2 with 11 articles.

HOLOTYPE.—NMV, male, 2.56 mm.

TYPE-LOCALITY.—VicFish 475, Western Port, Victoria, Staion 300–769–3, 57 feet, 15 July 1969.

MATERIAL.—VicFish, Western Port, 7 samples (8).

DISTRIBUTION.—Western Port, Victoria, shallow water.