CHAPTER V 







THE LAMELLIBRANCHIA 



CLASS IV. THE LAMELLIBRANCHIA, BLAINVILLE 



( = ACEPHALA TESTACEA, Cuvier ; CoNCHiFERA, Lamarck ; 

 PELECYPODA, Goldfuss ; LIPOCEPHALA, Ray Lankester). 



Order 1. Protobranchia. 

 Sub-Order 1. Solenomyacea. 

 2. Nuculacea. 



Order 2. Filibranchia. 

 Sub-Order 1. Arcacea. 

 2. Trigoniacea. 



3. Mytilacea. 

 4. Pectinacea. 

 5. Dimyacea. 



Order 3. Eulamellibranchia. 

 Sub-Order 1. Ostraeacea. 

 2. Submytilacea. 

 3. Tellinacea. 

 4. Veneracea. 

 ,, 5. Cardiacea. 

 6. Chamacea. 



7. Myacea. 

 8. Adesmacea. 

 9. Anatinacea. 



Order 4. Septibranchia. 

 Sub-Order. Poromyacea, 



Definition. The Lamellibranchia are Molluscs with an internal 

 and external symmetry. The cephalic region is rudimentary, and 

 the mantle, divided into a right and a left lobe, secretes a bivalve 

 shell which covers and encloses the whole body. The cephalic region 



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