Art. XV.—On two new Isopods. By Charles Chilton, M.A. [Read before the Philosophical Institute of Canterbury, 6th April, 1882.] Plate XXIIA. Genus Cymodocea, Leach. (Generic characters given in Miers' Catalogue N.Z. Crustacea, p. 113.) Cymodocea cordiforaminalis, sp. nov. PI. XXIIA., fig. 1. Body rather convex, slightly more than twice as long as broad. Head much broader than long, eyes rather large. Segments of thorax smooth, or only minutely granular, coxæ of all densely covered with rather long, very fine, woolly setæ. First segment rather longer than the others, next five equal in length, last longer, produced backwards at its postero-inferior margin, posterior margin slightly convex, overlapping the abdomen. Abdomen of two segments; the first showing on each side impressed lines indicating that it is composed of three or perhaps of four segments, having an irregular row of small rounded tubercles, posterior margin straight in the centre, produced backwards on each side into the last segment. Last segment very convex, bearing on the convex part several round tubercles of various sizes, the largest being near the median line and in the anterior part of the segment. The two lateral portions on each side of the terminal notch produced backwards and inwards, so as to meet in the median line, the central tooth small and sharply-pointed, so that what is really the terminal notch appears as a heart-shaped opening in the end of the abdomen. Last pair of pleopoda with the rami equal, reaching very slightly beyond the end of the abdomen. Inner ramus with its inner edge entire, outer margin at first entire but distally curved and irregularly toothed and fringed with setæ. Outer ramus thickest about the middle, proximal portions of margin entire, distal portions dentate, more distinctly so at the extremity, and fringed with setæ. Inner antenna with first joint of peduncle very stout, second also stout, third as long as the first but slender, being about four times as long as broad; flagellum shorter than the peduncle, of about 9–10 joints, bearing simple auditory cilia. Outer antenna with peduncle of five joints, first three subequal, fourth a little longer, fifth nearly twice as long as the fourth, narrow at proximal end but widening distally; flagellum longer than peduncle, of about 15 joints, each bearing a small tuft of short setæ. First pair of legs with basos and ischios long, the latter bearing on its outer distal margin four or five short stout setæ, meros broader than long, carpus small, propodos ovate with setæ on inner edge, some being plumose, dactylos large and strong, the end forming a claw distinct from the basal portion.