BULLAD^. 



Ill 



Cylichna ( Loven ). Shell solid, cylindrical, 

 rolled ; truncate. Animal short and broad, not 

 investing the shell ; tentacle-lobes united. 



C. cylinclracea. Fig. 158 ; n, s. 

 conulus. 

 mammillata. 

 nitidula. 



C. obtusa. 

 strigella. 

 truncata. 

 ■umbilicata. 



158 



CZ9 



159 



160 



161 



Acera (Muller). Shell thin, flexible, swollen; 

 aperture long, expanded, and deeply notched in 

 front ; pillar open, exposing the whorls. Animal 

 with a short, truncate head ; no eyes ; side-lobes 

 nearly concealing the shell. 



A. bullata. Fig. 159 ; n. s. 



Bulla (Lamk.). Bubble. Shell swollen, rolled, 

 partly or entirely external, perforated at the sum- 

 mit ; lip sharp. Animal with a large head, two- 

 lobed behind; side-lobes very large, turned up 

 on the shell ; hind-lobe covering the spire ; foot 

 four -sided. 



B. CrancbiL 



bjdatis. Fig. 160; «. 5. 



