SYNOPTICAL TABLE OF CLASSIFICATION. 



Tribes. 



1. INOPERCU- 



LATA 

 (without opercu- 

 lum). 



CLASS L— CEPHALA (with head). 



Orders. Families. 



1. Limacinea. 



\.PTJLMONIFERA\ 2. Colimacea. 

 (breathing air only) . 



\ 3. Auricidacea. 



9. 



10. 



11. 



U2. 



2. VULMOBKAN- 1. Lymnceacea. 2 



CHI AT A ! o" 



(breathing both air | 



and water) . I 4. 



' \. PULMONIFERA \.Cyclostomacea\ ~ 



■'breathinar air only) . <• 



Genera. 



Aeiojst. 

 G-eomaiactts. 



LlMAX. 



Testacella. 



VlTEINA. 



SlTCCINEA. 

 ZONITES. 



Heetx. 



Bttlimtts. 



Ztja. 



AZECA. 



achatina. 



Clausilia. 



Balea. 



Pupa. 



Yeetigo. 



Caeychium. 

 conovulus. 



Platstoebis. 

 Phtsa. 



Ltmma. 

 Ancyltjs. 



Cyclostoma. 

 Acme. 



2. OPEECULATA <■ 

 (with operculum). 



2.BBANCHIFERA 

 (breathing water 

 only). 



( 1. Littoracea. 



2. Peristomata. 



3. Neritacea. 



1. Assiminea. 





Bythinia. 

 Paltjdina. 

 Valvata. 



1. Neeitina. 



CLASS II.— ACEPHALA (without head). 



LAMELLIBEAN- 

 CHIATA 



(lamella-gilled). 



Orders. 



1. UNIMUSCU- 



LOSA 

 (one adductor 

 muscle). 



2. BIMUSCTJLOSA 

 (two adductor 

 muscles) . 



Families. 

 1. Mytilacea. 



1. Naiades. 



2. Cardiacea. 



Genera. 

 1. Deeissena. 



1. Anodonta. 



2. Unio. 



( 1. PlSIDIUM. 



i 2. Cyclas. 



