GASTEROPODA : PATELLID^. 



485 



IANTHINID^E. This Family is represented by the 

 Violet-Snail and its half-dozen allies. 



Fig. 420. 



lanthinafragilis, Lam. Atlantic. 

 a, raft ; b, egg capsules ; c, gills ; d, tentacles and eye-stalks. 



Fis 



421. 



FlSSURELLID^E, OR KEY-HOLE LlMPET 



FAMILY. - -This Family embraces gas- 

 teropods which have the shell conical, 

 and apex recurved. There are about 

 two hundred living, and one hundred 

 fossil species. Marine. 



CALYPTR^EID^E, OR BONNET-LIMPET FAMILY. - This 

 Family contains gasteropods which are found adhering 



Fig- 4 2 3- 

 Fig. 422. 



Fissurella Lister i. Orb. 

 West Indies. 



Calyptrcea equestris, L. 

 Philippines. 



Crepidulafomic&ta, Say. 



Fig. 424. 



New England. 



to stones and shells, most of them never quitting the spot 

 where they first settle. There are one hundred and sixty 

 living, and one hundred fossil species, all marine. 



PATELLID/E, OR LIMPET FAMILY. 

 This Family comprises gastero- 

 pods which have the shell conical, 

 with the apex turned forward. 

 There are more than one hundred 

 living, and one hundred fossil species. 



Patella testiidinalis, Mull. 

 Coast of New England. 



