[Read before the Otago Institute, 10th September, 1878.]

Fam. Oniscidæ. Sub-fam. Scyphacinæ.

Genus Actæcia, Dana, U.S. Explor. Exped., XIV. Crust., p. ii., p. 734.

Antennæ very stout, not distinctly geniculate at the fifth joint; flagellum indistinctly 5–6-jointed, exclusive of the minute apical joint. Terminal joint of maxillipeds broad and serrately lobed. Feet of the seventh pair as long as the others.

After his description of Scyphaæ ornatus, Dana describes and figures a smaller specimen which was found at the same time and in the same locality, and which he suspects may be the young of that species. Besides many minor points of difference, however, it is quite distinct from the generic character of Scyphax, in possessing the seventh pair of legs of normal size. He remarks, that if this is a new species, it is also a distinct genus, and suggests that it may be named Actæcia euchroa as designated in his earlier MSS. The species found by Mr. Jennings on the Auckland Islands, being evidently an Actœcia, I have drawn up the above generic character. The genus therefore contains the following species:—

1. Actœcia euchroa, Dana.

Body elliptic, abdomen not abruptly narrower than thorax. Head short, transverse. Eyes rather large and prominent. Antennæ short, curving outwards, surface minutely spinulous. Last thoracic segment not shorter than the preceding. Abdomen filling the concavity below the last thoracic segment, and forming a semicircle beyond it. Third, fourth and fifth abdominal segments much produced backward on either side. Last segment smallest, not projecting between the stylets, which are placed close together. Large branch of stylets very short and obtuse; smaller branch quite slender and arising from a point far anterior to the base of the larger branch.

Surface of thorax and abdomen with a few very short scattered spinules. Length 2 lines.

Bay of Islands–Parua Harbour (Dana).

2. Actœcia aucklandiœ, nov. sp.

Body narrow-oblong, abdomen narrowing gradually from the thorax. Head triangular, widest in front; anterior margin nearly straight, rounded at the corners; eyes situated above the angular projections. Segments of thorax subequal, more or less acutely produced posteriorly. Two first segments of the abdomen partly covered by thorax; last segment (sixth) much narrower than preceding, broadly triangular, and with obtuse apex. Caudal stylets subequal, only about half as long as abdomen; inner rami placed