Chlamys celator Finlay, 1928
FINLAY, H. J. 1928. The recent Mollusca of the Chatham Islands. Transactions and Proceedings of the Royal Society of New Zealand, 59: 232-286. [p. 268, pl 42, figs. 49, 50]
«Chlamys celator n. sp. (Figs. 49, 50).
Shell very similar to C. zelandiae (Gray), but much larger, and with stronger, more prickly ribs; living in sponges. There are somewhere about a dozen main ribs on each valve; those of the right valve double, and separating into two or three near margin; those of the left valve single, and thus apparently more distant. More or less regular primary, secondary, and tertiary interstitial riblets, in decreasing order of prominence, are present; this arrangement is better marked on left valve, the interstitial ribs on right valve being finer and more or less equal. All ribs, especially main ones, studded with sharp, high, narrowly spout-like scales. This sculpture is just that of zelandiae much exaggerated. The shell, too, has much the same style of build, but is notably less elongated, the dorsal margins sloping less steeply and spreading outwards lower down. Shell rather more inflated, and still ruder in growth-habit than zelandiae, i.e., there are frequent kinks in the shell, the convexity and the outline of basal margin are highly irregular. This feature is characteristic of the zelandiae as opposed to the radiatus forms. Apparently normally living in sponges, every fresh specimen seen -being totally incrusted with them; never found attached to rocks on the littoral. Length, 40 mm.; height, 43 mm. Locality: Stewart Is. (type; common); South Island beaches; Chatham Is., common. This is Suter's "subsp. gemmulatus" of C. zelandiae, but not, as Iredale has noted (1915, p. 486), gemmulatus Reeve. His description is not very good, but his figure and localities show that he had this form in mind. Whether it is really the Forsterian regional representative of the Cookian zelandiae, I am uncertain, so I have taken the safest course of describing it as a distinct species; it is unquestionably closely allied in habit and sculpture, but the habitat is notably different, while, on the other hand, there is another species in the south that lives under rocks and on roots of seaweed, just as zelandiae does in the north. This form is distinct from both the others and is described below as C. suprasilis n. sp. The two new species are both found fossiI in the Upper Pliocene beds at Castlecliff, but true zelandiae is not. A specimen of zelandiae (from Motutapu Island, under stones at low water) is here illustrated (Fig. 51) for comparison with celator. C. zelandiae (Gray) and C. grangei Murdoch, 1924, should be added to the list of New Zealand Chlamys given by Marwick (T.N.Z.I., vol. 58, p. 453, 1928), these two species being inadvertently omitted.» HAROLD JOHN FINLAY, 1928
|
H. J. Finlay, 1928, plate 42.
|