CLAMS, OYSTERS, AND MUSSELS 123 



CLASSIFICATION OF THE EXAMPLES 



Branch X — MoUusca. 

 Class — Pelecypoda. 



Order — Pseudo-lamellibranchia. 

 Types of Order. 



Ostrea virginiana — Oyster. 

 Meleagrina margaritifera — Pearl oyster. 

 Order — Eulamellibranchia. 

 Types of Order. 



Unio complanata — River mussel. 

 Mya arenaria — Long clam. 

 Venus mercenaria ■■ — Quahog, or Round clam. 

 Class — Gasteropoda. 

 Order — Pulmonata. 

 Types of Order. 



Physa species — Pond snail. 

 Limncea species — Pond snail. 

 Planorbis species — Pond snail. 

 Paludina species — Pond snail. 

 Helix alboldbris — Land snail. 

 Limax flavits — Slug. 

 Class — Cephalopoda. 

 Order — Decapoda. 

 Types of Order. 



Loligo pealii — Squid. 

 Sepia officinalis — Cuttlefish. 

 Order — Octopoda. 

 Type of Order. 



Octojms vidgaris — Octopus. 



