SPHENIA. 



357 



rnodesta, Hinds. 

 moailis, Hinds. 

 nasuta, Sow. 



Newtoniana, C. B. Adams. 

 nuciformis, Sow. 

 obesa, Hinds. 

 operculata, Phil. 

 rosea, Brown. 

 rotalis, Hinds. 

 rubra, C. B. Adams. 

 scaphoides, Hinds. 

 semen, Lam. 



similis, Hinds. 

 solidula, Hinds. 

 speciosa, Hinds. 

 sulcata, Brufj. 

 Swiftiana, C. B. Adams. 

 Taheitensis, Lam. 

 tenuis, Sow. 

 trigona, Hinds. 

 truncata, Hinds. 

 tunicata, Hinds. 

 variegata, Adams and Reeve. 

 ventricosa, Adams and Reeve. 



Sub-gen. azara, D'Orbigny (Potamornya, Hinds). 



Sbell nearly smootb, covered witb an olivaceous epidermis. 

 Hinge with the cartilage-plate broad and spatulate ; two obscure 

 teeth in the right valve. Estuary. 



adusta, Hinds. 

 sequalis, C. B. Adams. 

 contracta, Say. 

 inflata, C. B. Adams. 

 labiata, Maton. 



nimbosa, Soiv. 

 ochreata, Hinds. 

 procera, Hinds. 

 trigonalis, C. B. Adams. 

 ustulata, Reeve. 



Genus SPHENIA, Turton. 



Siphons produced, united. 



Shell oblong, inequivalve, produced and gaping posteriorly, 

 surface smooth or rugose, covered with an epidermis, beaks 

 incurved. Hinge composed of an erect, dilated, laminar 

 tooth in front of the oblique, triangular cartilage-pit in the 

 right valve, with a corresponding pit in the left ; cartilage 

 internal. Pallial impression slightly sinuated. 



Ex. S. Binghami, Turton, pi. 95, fig. 4. Shell, S. 

 Binghami, fig. 4, a, 4, b. 



VOL. II. 3 A 



