AND DESCRIPTIONS OP NEW SPECIES. 99 



exhibiting the undulations of the beaks; nacre very thin and slightly 

 salmon coloured, darker in the cavity of the beaks. 



Remarks. — This very small species was brought from Calcutta by 

 Mr Blakie, with the U. cxruleus (Nob.). Both were procured about 

 one hundred miles above that city. It resembles, in its outward char- 

 acters, the young of S. cygnea {Jlnoil. cygnea, authors). It is, how- 

 ever, more transverse, and differs altogether in the formation of the 

 hinge, which is furnished with perfect cardinal and lateral teeth. In 

 the peculiar character of the double tooth in the right valve, it resem- 

 bles the S. ochracea.* The bilineata is easily distinguished by the 

 two delicate lines which pass from the beaks to the posterior margin. 



Symphynota Inflata. Plate XIV. fig. 28. 



Testa cwato-triangulari, inaquilaterali, ventricosd; valvulis pertenuibus, ccnmato- 

 bialatis; dente cardinali in valvuld singula unico; dentibus lateralibus ad terminos 

 laminatis; natibus prominulis; ligamento celato; margarita purpurea. 



Shell triangular-ovate, inequilateral, ventricose; valves very thin, elevated into two 

 wings, both of which are connate ; cardinal tooth single in both valves ; lateral teeth 

 bladed towards their termination ; beaks slightly prominent ; ligament concealed ; 

 nacre purple. 



Hab. Alabama river. Judge Tait. 



My Cabinet. 



Cabinet of Professor Vanuxem. 



Cabinet of P. H. Nicklin. 



Cabinet of the Academy of Natural Sciences. 



Diam. 1 -6, Length from the beaks to the base, 2-4, Breadth 4-5 inches. 



Length from the top of the wing to the base, 3-7 inches. 



Shell triangular-ovate, ventricose, transversely and finely wrinkled ; 

 substance of the shell thin ; valves elevated into a broad high wing pos- 

 terior, and a small one anterior to the beaks, and connate in both ; pos- 



* See vol. ill. p. 45.'j. 



