Page:Transactions NZ Institute Volume 15.djvu/101

ends. The first pair of pleopoda are modified so as to form an operculum covering the others; one of the plates, the outer I think, is long and broad so that it extends along the whole of the under side of the pleon; the inner plate appears to perform no special function, it is small and narrow, apparently becoming rudimentary (fig. 4f). The setæ on the pleopoda are long and fringed on each side with long plumes, which are exceedingly delicate.

This species was described by Mr. Miers from specimens in the collections of the British Museum. His specimens appear to have been imperfect, for he neither describes nor figures the antennæ. I have found it abundantly at Eyreton, and also in the bush at Oxford. The inner antennæ are very small and composed of three joints, the basal one stout, second short and narrowing distally, third about twice as long as the second, much narrower, with a few short setæ at the end (pl. I., fig. 3a). The outer antennæ consist of seven joints. The basal one is short, the second and third subequal and rather shorter than the fourth; the fifth joint is the longest, and is longer than the flagellum, which consists of two joints, the first short, very slightly longer than broad, the second more than three times as long as the first and followed by a minute terminal joint which bears two or three short setæ; the whole antenna, but more especially the distal portion, is finely hirsute, the hairs being short and delicate, much more so than can be shown in the figure (pl. I., fig. 3b).

In describing the last segment of the abdomen, Mr. Miers says: "terminal segment much the broadest at the base, with the sides at first converging and then parallel." In my specimens the sides after converging usually diverge slightly.

The colour varies considerably. It is usually yellowish-brown with darker patches, but some specimens are uniformly black.

Over the whole body the integument is covered with peculiar scale-like markings, each scale being usually more or less pointed at the end (pl. I, fig. 3c).

In a previous paper I have identified specimens found at Christchurch and Eyreton as this species, and at the same time adduced reasons for believing that it could not well have been introduced from Europe. Since then I have found specimens precisely similar in the bush at Oxford, so that I think there can be little doubt that it is really a native of New Zealand and has not been introduced.