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The Ark shells are to be found in the sea, and on the sands and mud on 

 the shores of the ocean, generally between low and high water marks. Some 

 of them are occasionally used as food. 



DIVISION I. With the teeth of the hinge in a straight line. 

 Family 1st. Shell twisted. 



Scientific name. 

 Tortuoso, 



Nose, 

 Irabricata, 



Navicularis, 

 Plicata, 



Magellanica, 

 Lace rata, 

 Fusca, 

 Bicolorata, 



Locality. 

 Amboyna, Red Sea. 



Scientific name. 



Family 2cZ. Shell rhomboidal. 



E. & W. Indies, Britain. Candida, 



W.Indies, Britain, Med., Indica, 



C. of Good Hope. Lactca, 



St. Domingo. Reticulata, 

 Red Sea. 



Locality. 



West Indies, Guinea. 

 Coromandel. 

 Britain, Mediterranean. 

 West Indies. 



Family 3d. Shell oblong or transversely ovate. 



Straits of Magellan. Modiolus, 



East Indies. Corbula, 



W. Indies, Madagascar. Senagalensis, 

 Red Sea. 



Med. W., Indies. 

 Nicobar Isle, C.G.Hope. 

 Mouth of the Niger. 



Laevigata, 



Pella, 



Antiquata, 



Complanata, 

 Barbata, 



Family 4th. Shell subcordate. 



Nicobar Isles. Granosa, 



Mediterranean, Spain. Rhombia, 

 E. & W. Indies, Africa. Senilis, 



Family 5th. Gaping. 



Guinea, Madagascar. 

 Med. & Red Sea, 



Nivea, 

 Cancellata, 



China, E. Indies. 



E. & W. Indies, Brazil. 



Guinea. 



Red Sea. 

 Curagoa. 



Family 6th. With an ear-shaped appendage in the interior of each valve. 

 Concamerata, Nicobar Isles. 



DIVISION II. With the teeth of the hinge in a curved line. 

 Family 1st. Subcordate. 



Campechensis, Campeachy, Carolina. Angulosa, Brazil, Africa. 



Equilatua, West Indies. 



