302 DR. <3r. a. BKADT ON ENTOMOSTRAOA 



the rigbt side being extremely gibbous and overlapping tbe left 

 in the middle of the dorsal margin. Hinge-margins without 

 teeth. 



Cyprinottjs cingalensis, n. sp. (Plate XXXVIII. iigs. 28- 

 30.) 



Shell, seen laterally, sub triangular, greatest height situated in 

 the middle and equal to nearly two thirds of the length ; anterior 

 extremity obliquely rounded and somewhat narrowed, posterior 

 broad, rounded, but somewhat flattened ; dorsal margin greatly 

 elevated, the highest point being just a little behind the middle, 

 thence sloping steeply and with a distinct sinuation towards both 

 extremities, ventral margin gently convex : seen from above, the 

 outline is ovate, compressed and pointed in front, rounded behind, 

 twice as long as broad, the greatest width in the middle ; the 

 dorsal surface marked in the middle by a deep longitudinal fur- 

 row. The internal surfaces of both valves show large semilunar 

 marginal flanges before and behind ; the hinge-margins are simple 

 and devoid of teeth ; the left valve is finely hirsute on the anterior 

 half of the ventral margin, which, however, bears no teeth, while 

 that of the right valve is denticulated throughout its whole 

 length, the teeth becoming gradually more pronounced towards 

 the posterior extremity. The surface of the shell is smooth, aud 

 marked throughout with closely-set impressed puncta. Colour 

 clouded gray, with diagonal bands of green on the posterior half. 

 The soft parts of the animal are in all respects, so far as I have 

 been able to ascertain, as in Cypris. Length -^ of an inch 

 (1*4 millim.). 



Four or five specimens were seen, all of them, I think, males. 

 The validity of genera founded solely on peculiarities of shell- 

 structure may often be reasonably doubted, but in this case the 

 divergence from the normal Cypris type is so marked as to make 

 the separation unavoidable. Moreover some of the Ostracod 

 genera, notably Cypris and Cytliere, are becoming so unwieldy by 

 reason of the large number of species referred to them, that 

 some subdivision either into genera or subgenera is, or soon will 

 be, a matter of necessity. And it is to be remembered that 

 characters derived from the shell, in an important palssontological 

 group like the Ostracoda, are valuable as being the only ones 

 accessible to students of fossils. 



