COLLECTED IK CEYLON. 299 



Ctpeis Halti, n. sp. (Plate XXXYIII. figs. 15-17.) 

 Shell, seen laterally, subtriangular, higher in front than behind ; 

 height equal to more than half the length ; anterior extremity 

 broad and evenly rounded, posterior also rounded, but much nar- 

 rower ; dorsal margin elevated and obtusely ahgulated in front 

 of the middle, thence sloping steeply backwards, but more gently 

 towards the front ; ventral margin slightly'convex : seen from 

 above the outline is almost boat-shaped, widest just in front of the 

 middle, tapering sharply to an acuminate extremity in front ; pos- 

 terior extremity wider, and showing on each valve a minute spine ; 

 width and height equal. Shell smooth, sculptured in a manner 

 precisely like that of the European species G. tessellata, Eischer. 

 Colour pale olive, with three or four indistinct transverse bands 

 of a darker hue. Length 3I3- of an inch ("77 millim.). 



It is curious that this species, so like G. tessellata in surface- 

 markings, should likewise present the same peculiarities of form. 

 It must, however, be borne in mind that a similar style of sculp- 

 ture is met with in the young of some species {G. obliqua, Brady, 

 G. affinis ?, Fischer) and disappears, wholly or partially, in ad- 

 vanced life. It is therefore just possible that G. Halyi may be 

 the young form of some other species. Only one specimen was 

 observed. 



Cypkis tenuicatjda, n. sp. (Plate XXXVIII. figs. 18-20.) 

 Shell, seen laterally, reniform, about once and a half as long as 

 broad, highest in the middle; extremities equal and well rounded ; 

 dorsal margin evenly arched, ventral slightly sinuated : seen from 

 above the outline is ovate, widest behind, and gradually tapered 

 towards the front ; extremities rounded, anterior very narrow, 

 almost acuminate, posterior very wide. Surface of the shell 

 smooth, but not polished, and sometimes showing a few very 

 short rigid hairs. Colour milky-white. Length gV ^f an inch 

 ("88 millim.). The postabdominal rami are unusually slender; 

 the terminal claws very long. 



Ctpeis fueptjeacea, n. sp. (P]ate XXXYIII. figs. 21-23 a.) 

 Shell tumid, subreniform : seen laterally, the extremities are 

 broadly rounded, dorsal margin very boldly arched, sloping more 

 gradually towards the front, ventral almost straight; greatest 

 height in the middle, and equal to about ''{wo thirds of the 

 length : seen from above, sub elliptical, with rounded, obtuse 

 extremities, somewhat narrower in front than behind; rather 



