Description of Female

Antennae. First: Flagellum of 6 segments, first 2 fused; slightly longer than peduncle. Second: Flagellum of 17 segments, first 3 or 4 fused; slightly longer than peduncle.

Gnathopods. First: Sideplate has long slender spines below basos insection. Basos width [ unclear: ] length. Merus larger than ischium, posterior surface spined. Carpus anterior margin nearly as long as basos and twice merus length, margins and surface strongly spined. Propod narrower, narrowing distally to stout curved dactylos which has stout short spine on inner margin. Propod [ unclear: ] carpus length, margins and surface strongly spined. Second: Sideplate subsquare. Gills anchor-shaped; broodplate as long as basos, width more than ½ length Basos posterior spine row set a little back from margin. Ischium subrectangular, width ½ length, as long as basos is wide. Merus subtriangular, convex, posterior and surface spined, posterior margin slightly longer than ischium; anterior margin contiguous, with proximal ½ of carpus posterior margin, the rest of which is free and convex. Carpus ⅔ basos length. Propod ovate, almost as long as carpus, widening a little distally, row of spines on propod surface to dactylos base. Dactylos has small row of spines on outer hinge, palm small, parallel to main propod axis, scabrous.

Localities. “On the shores of Kapiti Island” (Filhol). “Banks of Waitohi Stream, Picton, at some distance from mouth”, coll Chilton, 11/7/1910; “on rocks at base of waterfall”, Kapiti Island, coll. Dr. Cockayne, 1906, Waitohi Stream Estuary, coll. Dr. Redman.

Hypotypes Slides A₁–A₄ (male), Tray 45, Chilton Collection; C.5 (female). Also: C.2, C.3, male, B₁–B₅, Tray 54, Chilton Collection (male); C 4, female.

Remarks. I have identified these specimens with Filhol's Orchestia dentata. The hypotypes are those which Chilton (1919) described and figured from Picton and Kapiti as Orchestia tucurauna Müller. Additional details are taken from other specimens from the Picton locality.

The original description of O. tucurauna (Fritz Müller, 1864) is extremely scant and could equally well include Stebbing's O. sulensoni (1899). The latter Chilton considered synonymous with O. tucurauna and his own specimens.

Stebbing's O. sulensoni differs from Chilton's O. tucuiauna, here described as Talorchestia dentata, in these respects.

Chilton disregards the first two of these as being merely growth differences. If they were all, he would probably have been justified. However, taken in conjunction with the last three which are not normally subject to much change with growth and seem very consistent, even specific, characteristics in this group of littoral amphipods, I believe they give good grounds for separation. A complete comparison of the two lots of specimens with particular attention to the maxillipeds, epimeral plates and pleopods would probably clarify the problem.

Müller's description of the male second gnathopod agrees reasonably with Stebbing's. The basos of Müller's female second gnathopod seems a little too dilated to belong to the same species as Chilton's specimens. Shoemaker (1932) suggests that Stebbing's Talorchestia fritzi may possibly be identical with Müller's species.

The distinctive features of Chilton's specimens, apart from the male second gnathopods, are the third uropod with its terminal brush of spines, and the shape of the epimeral plates in which the posterodistal angle is produced slightly backwards and armed with strong spine. In most species, the extremity of this angle is free from spines.

In his specific diagnosis, Chilton says “palm nearly transverse in old males, more oblique in younger individuals”. In his discussion he states, “in the second (gnatho-