Description of Female
Antennae. Second: Flagellum has 13 segments.
Gnathopods. First: Carpus nearly basos length, posterior free margin and surface have strong spines but lack scabrous pellucid lobe of male. Propod slightly more than ½ carpus length, narrowing a little distally; posterodistal angle a little produced in small seta-tipped lobe forming what could be regarded as a small palm, Strong curved dactylos more than ½ propod length. Second: Sideplate subsquare, ventral and posterior margins and surfaces sparsely spined. Basos widest medially, width not quite ½ length, a few spines on straight posterior margin; sinuous anterior margin has regular small spines. Ischium subrectangular, width ½ length, length ⅓ basos, margins spined. Merus subrectangular, width ½ length, length ⅓ basos, margins and surface spined, anterior margin contiguous with proximal ⅓ of carpus posterior margin. Carpus ½ basos length, margins strongly convex, anterior spined; free ⅔ of posterior margin expanded to scabrous pellucid area with a few minute spines on surface. Propod ⅔ carpus length, anterior margin straight, spined; posterior expanded in scabrous pellucid lobe distally past small oblique palm; median surface of propod has numerous small spines; palm has small spines. Small stout curved dactylos as long as palm.
Peraeopods First: Sideplate subrectangular. Fourth: Merus proportionately narrower than in male. Carpus as long as merus, slightly narrower, widening very little distally, spined like merus. Otherwise peraeopods as in male, segments a little less spinous.
Localities “On the shores of Cook Strait, in Massacre Bay, and on the West Coast of the South Island at Hokarita” (Filhol); Puysegur Point; Bluff; Waipapa Point; Golden Bay; Stewart Island; Green Islets; Kaikoura; Preservation Inlet; Riverton; Moeraki; (these Chilton Collection references); “shingle beaches of South Island,” McIntyre (unpublished MSS).
Hypotypes. Tray 36, Slides M1-M5, male; B1-B5, female, Moeraki, Chilton Collection. Also: Slides C.16, male, C.17, female.
Remarks. Stebbing's descriptions of Talorchestia tumida (Stebbing, 1887, 1906), based on specimens received from G. M. Thomson, make it clear that the specific name tumida was first applied to specimens having the palm, as Chilton says, “more
like that shown by Stebbing (1887)”. The Chilton Collection contains specimens from several localities showing differences from those described by Stebbing, and others obviously conspecific with Stebbing's material. I consider there are sufficient differences to regard the specimens from Moeraki, New Zealand, as a distinct species. I have described these above. It would appear to be on these that Chilton (1917) based his description and figures of Talorchestia tumida.
Distinctive characteristics are the palm of the second gnathopod in the male which is excavate anteriorly and is not strongly toothed as in T. tumida G. M. Thomson; the sideplates, particularly those of peraeopod 3; and the uropods.
There is a suggestion of a palm in the female first gnathopod on which the species could be classed as Orchestia, but in view of the obviously close affinities with other Talorchestia species, and the shape of the second peraeopod dactylos, I do not consider that this would be a natural classification.
Chilton remarks that most of his specimens were found “near highwater mark,” whereas Thomson records T. tumida “on sandy beaches and sandhills, usually at some distance from the sea”. This appears to be a true distinction in habitat between T. tumida and T. cookii.
Filhol's descriptions and figures are on the sparse side, but the specimens de scribed above agree satisfactorily with what he does give.
Talorchestia tumida G. M. Thomson, 1885. (Figs 49–70.)
Talorchestia tumida G. M. Thomson, 1885: 577.
Thomson and Chilton, 1886° 145.
Stebbing, 1886: 5.
Stebbing, 1887: 202, pl. 39, fig. A.
G. M. Thomson, 1889: 260, pl. 13, fig. 4–8.
Chilton, 1892: 259. Stebbing, 1906: 550
(with synonymy). Chilton, 1917: 296–299 (partim).
Chilton, 1927: 175. Stephensen, 1935: 12.
Stephensen, 1948: 13.
Paviour-Smith, 1956: 533, 552.
Orchestia gammarellus Della Valle, 1893: 501. (partim).
Orchestia tumida G. M. Thomson, 1899: 203