19 



LETTER III. 



CATOCYSTI, DIVIDED INTO FIBULAE, CASSIDES, SCUTA, AND PLA- 



CENTk FIBULA, SUBDIVIDED INTO CONULI AND DISCOIDES 



CASSIS, SUBDIVIDED INTO GALEJE AND GALEOL^, INCLUDED IN 



ECHINOCORYS SCUTUM, ECHINANTHUS PLACENTA, ECHI- 



NODISCUS ECHINOCYAMUS-. 



W E now arrive at the second grand division, or family, of Echini, 

 CATOCYSTI, the opening for the vent of which is in some part of the 

 base of the shell. The first section under which these are arranged by 

 Klein is that of Fibula, a name which is generally adopted ; although 

 the echini it includes bear no resemblance to fibulae, but rather to 

 clothes'-buttons, to which the word is now made to apply. These 

 echini are divided into two genera. The first, conulus, contains those 

 which rise from a circular base into a cone, with an acute or obtuse ver- 

 tex, from which five pair of punctated or crenulated lines, or ambulacra, 

 pass, dividing the shell into five large and five small areae, that in which 

 the anus is placed being Tather the largest." By some oryctologists these 

 have been termed Bufonita and Scolopendrita, and by others, Pilei ; and 

 by the English Capstones. 



The species which constitute this genus are only known as fossils, and 

 are so variously distinguished by the modification of their forms, and 

 by other little circumstances, as to render their varieties too numerous 

 to admit of being specified. 



Conulus albogalerus, Lesk. E. albogalews, Linn, deriving its name from 

 the white conical caps of the priests of Jove, is the first species of this 



