Zoological Society. 



151 



Family 9. Cardiacea. 

 Cardium. Cardita. 



Isocardia. Cypricardia. 



Family 10. Ai'cacea. 

 Cucullaea. Pectunculus. 



Area. Nucula. 



Family 11. Trigonacea. 

 Trigonia. 



Family 12. Naiades. 

 Unio. Iridina. 



Hyria. Mycetopus. 



Anodon. 



Family 13. Chamacea. 

 Etheria. Chama. 



Order 2. Unimusculosa. 

 Family 1. Tridacnacea. 

 Tridacna. Hippopus. 



Family 2. Mytilacea. 

 Lithodomus. Mytilus. 



Modiola. 



Pinna. 



Family 3. Aviculacea. 



Crenatula. Vulsella. 



Perna. Avicula. 

 Malleus. 



Family 4. Pectinacea. 



Pedum. Plicatula. 



Lima. Spondylus. 

 Pecten. 



Family 5. Ostracea. 



Ostrsea. Placunanomia. 



Placuna. Anoraia. 



Class 2. BRACHIOPODA. 



Family 1. Tendinosa. 

 Lingula. Terebratula. 



Family 2. Adhcerentia. 

 Tliecidium. Orbicula. 



Crania. 



Class 3. GASTEROPODA. 



Order 1. Cirrhobranchiata. 

 Dentalium. 



Order 2. Cyclobranchiata. 



Chiton. Patella. 



Chitonellus. 



Order 3. Cervicobranchiata. 



Family 1. Fissuracea. 



Lottia. Emarginula. 



Siphonaria. Fissurella. 

 Parmophorus. 



Family 2. Capulacea. 

 Crepidula. Hipponyx. 



Calyptrsea. Pileopsis. 



Family 3. Macrostomata. 

 Velutina. Stomatia. 



Sigaretus. Haliotis. 



Family 4. Tubispiracea. 

 Siliquaria. Vermetus. 



Order 4. Pleurobranchiata. 



Family 1. Bullacea. 



Bulla. 



Family 2. Semiphyllidiana. 

 Pleurobranchus. Umbrella. 



Family 3. Aplysiana. 

 Aplysia. Dolabella. 



Order 5. Nucleobranchiata. 

 Carinaria. 



