FRESHWATER AND LAND SHELLS. 1 1 



Unio TURGiDUS. Plate V. fig. 11. 



Testa subrotunda, inflata, tuberculata, subcBquilaterali; vahulis crassis ; natibus elevatis ; 

 dentibus cardinalibus grandibus compressisque ; lateralibus brevibus subrectisque ; margarifa 

 alba et iridescente. 



Shell subrotund, inflated, tnberculatedj nearly equilateral; valves thick ; beaks ele- 

 vated; cardinal teeth large and compressed; lateral teeth short and nearly straight ; 

 nacre white and iridescent. 



Hab. near New Orleans. Mr Barabino. 



My Cabinet. 

 Diam. 1, Length 1-3, Breadth 1-6 inches. 



Shell nearly round, inflated, tuberculated, nearly equilateral, suban- 

 gular behind ; substance of the shell thick ; beaks thick and elevated ; 

 umbonial slope scarcely elevated; ligament short and thick ; epidermis 

 dark brown ; tubercles small, crowded on the umbones, and sparse to- 

 wards the margin ; cardinal teeth very large, compressed, the anterior 

 section being much elevated and much enlarged ; lateral teeth short and 

 nearly straight ; anterior cicatrices deeply impressed and distinct ; pos- 

 terior cicatrices distinct, the smaller being scarcely visible ; dorsal cica- 

 trices placed on the inferior part of the cardinal tooth ; palleal im- 

 pression deep ; cavity of the shell rounded ; cavity of the beaks deep 

 and angular; nacre pearly white and iridescent. 



Remarks. — For several specimens of this species I am indebted to the 

 kindness of the late Mr Barabino. It has more resemblance to the U. 

 pustulosus (nobis) than any shell with which I am acquainted, but dif- 

 fers in being more inflated, in the number, size and position of the tuber- 

 cles. In i\\Q pustulosus {\i^se are large and more frequent towards the 

 basal margin, the beaks being nearly devoid of them, while in the turgi- 

 this they are numerous on the umbones and towards the beaks. In the 

 cardinal teeth there is a still greater disparity. In the former species 

 these are spread out, while in the latter they are compressed, and pre- 

 sent a very remarkable character in the great elevation of the anterior 

 section. The large ray, so generally found on the pustulosus, is not 

 found on the specimens which I have seen of turgidus. This or more 

 may perhaps be found on perfect or young individuals. 



