132 



CL hemisphcericus and Cl. qvinquelabiatus are names 

 given to two mutilated fossil specimens, possessing, in Leske's 

 opinion, uncertain claims to places under this genus. The 

 first, he thinks, resembles galea wagrica, Klein ; and the 

 second does not appear to have been in a state, the vent not 

 being discoverable, to allow a correct judgment being formed 

 respecting even its generic characters. 



GENUS IV. Cassidulus. Ovate or subcordiform, and 

 rather raised ; the mouth beneath, subcentral ; the vent at 

 one end, considerably above the margin ; the ambulacra 

 porous, subpetaloidal, and reaching nearly to the margin. 

 PI. ii. fig. 7. 



These echinidae were pointed out by Leske as requiring 

 to be placed under a distinct and new genus, the mouth 

 being placed nearly in the centre of the base, and bearing 

 the character of echinanthus ; the vent situated on the upper 

 part of one end, as in spatagus. Leske having declined 

 giving a name to the genus, it received it from Lamarck. 



Sp. 1. Cass. pyriformis. Ovate and gibbous, the base 

 rather flat ; the surface, particularly of the base, tubercular ; 

 and the back slightly carinated ; the ambulacra obsoletely 

 porous ; the mouth roundish, subpentagonal, and with five 

 rather prominent lips ; a double row of pores, forming a five- 

 rayed star, round the mouth ; the vent round. Fossil. 



2. C. lapis cancri. Convex and obtusely ovate ; the 

 vertex excentric and perforated with four pores ; the am- 

 bulacral lines of pores double, and forming subpetaloidal 

 figures, with the terminations open ; the mouth not exactly 

 in the centre, but nearer to the narrower end ; the vent 

 round. Fossil. 



3. C. patellaris. Oval and flattish ; the back very 

 slightly raised, and the base as slightly concave ; the am- 

 bulacra biporous ; the pores linearly connected in the form 

 of a star, and rather separated from the rest of the surface 

 by an almost obsolete line. 



