4 Dr. W. Bairtl on new l^atomostracous Crustacea, 



spine, while the left valve is rounded and free from any such 

 prolongation. The valves are nearly equal in breadth, and do 

 not overlap each other at their ventral margin, but appear to fit 

 into a slight groove, which, when viewed from the interior, may 

 be seen to run all round the ventral margin and the edges of 

 both extremities. The sctse on the pediform antennse are five in 

 number, long, and finely plumose. 



Length 2 lines ; breadth 1 line. 



Hab, Sandwich Islands j W. Newcomb, Esq. Jamaica ; E. 

 Chitty, Esq. 



• 2. Cijpris Texasiensis, Baird. PI. I. figs. 3, Sa. 



Carapace of an ovoid shape, narrowed and somewhat flattened 

 anteriorly, considerably swollen and tumid posteriorly, and of a 

 dull uniform white colour, with the exception of the margin of 

 the anterior extremity, which is of a dark hue. Ventral margin 

 nearly straight, or only slightly sinuated, but distinctly marked 

 with a notch near the anterior extremity, somewhat resembling 

 that of a Cypridina. Dorsal margin rounded, as well as both 

 extremities. The two valves fit closely to each other. The sur- 

 face of the carapace is quite smooth and shining or only slightly 

 punctate, the punctations being only visible when under a high 

 power. Lucid spots placed near the middle of the valve. 



Length 1| line; breadth at broadest part 1 line. 



Hab, Texas ; Mr. Cuming. 



As only the empty carapace remains, I was unable to distin- 

 guish whether this species belongs truly to the genus Cypris or 

 {^andona. - 



3. Cypris Chittyensis, Baird. PI. I. figs. 4, 4 «, b. 



Carapace elongately elliptical, narrow, and of a uniform green 

 colour, marked here and there with streaks of a darker green 

 hue. The ventral margin is sinuated in the centre ; the dorsal 

 margin and the two extremities, which are both of equal size, 

 are rounded. External surface of carapace quite smooth and 

 shining. The edges of the valves, especially internally, are 

 strongly sulcated, and at either extremity there is, on the inside 

 of the shell, a kind of shelf which is also strongly striated. The 

 posterior shelf appears the larger of the two. Pediform antennse 

 each furnished with a bundle of about four or five setas, which are 

 of exactly the same length as the antenna, but are not plumose. 

 The caudal filaments are of a peculiar form ; they are of mo- 

 derate length, flattened, and differing from each other in some 

 respects. One of them is strongly serrated or toothed on its 

 outer edge, while the other (which is somewhat narrower) is 

 simple, or is without, the strong teeth or serrations which cha- 



