74 



They have been distributed into sections in the 

 following manner : 



1. Scutifera. Body elongate, attached the whole 

 length of the foot; mantle shield-like, with a 

 small internal shell. (Limacina.) 



1. Limax (fig. 29.). 



2. Cochleophora. Body more or less spiral, 

 prominent on the (middle generally) upper sur- 

 face of the foot, and covered with a more or 

 less spiral shell. Sometimes partly hidden by 

 the reflexed part of the produced edge of the 

 mantle. 



* Mantle produced in front, and partly extended 

 over the shell. (Vitrinina.) 



2. Vitrina. Shell depressed, polished; mouth 



semilunar, large ; peristome thin. 



* Mantle enclosed, not produced in front. 



3. Zonites. Shell depressed, polished; mouth 



semilunar ; peristome thin, acute. 



4. Helix. Shell subglobose or depressed, striated ; 



mouth semilunar ; peristome rather thickened 

 and reflected. 



5. Succinea. Shell oblong, elongate ; mouth very 



large, oblong ; peristome thin. 



6. Bulimus. Shell oblong, elongate, striated; 



mouth moderate, ovate, toothless. 



7. Zua. Shell oblong, elongate, polished ; mouth 



moderate, ovate, with a thickened internal 

 edge. 



8. Azeca. Shell oblong, elongate ; mouth mode- 



rate, toothed, with a thickened internal edge. 



