188 Transactions. — Zoology. 



Art. XV. — On two new Isopods. By Charles Chilton, M.A. 

 [Read before the Philosophical Institute of Canterbury, &th 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, coxae of all densely covered with rather long, 

 very fine, woolly setae. 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. Ab- 

 domen 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 ter- 

 minal 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 setae. Outer ramus thickest about the middle, proximal portions of 

 margin entire, distal portions dentate, more distinctly so at the extremity, 

 and fringed with setae. 



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 dismally; flagellum longer than 

 peduncle, of about 15 joints, each bearing a small tuft of short setae. First 

 pair of legs with basos and ischios long, the latter bearing on its outer 

 distal margin four or five short stout setae, meros broader than long, 

 carpus small, propodos ovate with setae on inner edge, some being plumose, 

 dactylos large and strong, the end forming a claw distinct from the basal 

 portion. 



