so UNIVALVES. BULLAr 



Helvola. Cruenta. 



Ocellata. Reticulata {Netted C.) 



Poraria. Rubigiiiosa Iron-mould C. 



*Pediciilus l^Sea Louse.) Miliaris. 



Nucleus ( Wrinkled C. ) Acicularis. 



BULLA.— Dipper or Bubble. 



Animal — a Umax: Shell vnivalve, corivolntef unarmed 

 vjith teeth: aperture a little siraitenedy oblong, lonc/itu- 

 dinaly verg entire at the base; inllar oblique^ sm.ooth. 



Tins genus, which contains fifty-two species, is in some 

 instances so nearly allied to the latter, i. e. the Cyprsea, 

 that much caution is necessary in order to prevent confu- 

 sion in the classification; for many of the Cypr3ea3, when 

 young, so nearly resemble some of the Bullae, that authors 

 liave actually intermixed the genera. However, one 

 grand mark of distinction in this genus is, that, in what- 

 ever stage of growth its species are found, they never 

 have teeth on both their lips; the pillar-lip being invari- 

 ably free from all sorts of denticulations or crenulations; 



