66 ON THE NAIADES, 



Remarks. — I am indebted to an amiable and intelligent friend, Mrs 

 Corrie of Birmingham, England, for this new species, which comes 

 from Calcutta; and to her I dedicate it, as a mark of sincere friendship. 

 It closely resembles the U. marginalis of Lamarck, but differs from 

 that species in being more transverse, in the beaks being more refuse, 

 in the dorsal line being nearly straight, and in its not being possessed 

 of a light border along the margin. The cardinal teeth are remark- 

 ably thin, and form nearly a line with the lateral teeth. 



Unio Grayanus. Plate IX. fisr. 26 



o* 



Testd lanceolata, transversissima, antice rotundata et postice acictissime angu- 

 lata, prope nates et partem posticam plicata ; lateribus planulatis ; clivo umboniali 

 subcarinato ; valvulis tenuibus ; natibus props marginem anticam locatis, de- 

 pressis ; epidermide luteold, obsolete radiatu ; dentibus cardinalibiis in valvuld 

 xitrdque duplicibus et erectis ; lateralibus longissimis, tenuibus, sub-erectisque ; 

 margarita pulchra et iridescente. 



Shell lanceolate, very transverse, rounded before and very acutely angular behind, 

 plicate about the beaks and posterior part of the shell, flattened on the sides ; umbonial 

 slope ridged ; valves thin ; beaks depressed, placed near the anterior margin ; epidermis 

 yellowish with obsolete rays; cardinal teeth double in both valves and erect ; lateral 

 teeth very long, thin and nearly straight ; nacre beautifully pearly and iridescent. 



Hab. China. 



My Cabinet. 

 Cabinet of Mr Hyde. 

 Cabinet of Mr Gray, London. 

 Diam. -6, Length -8, Breadth 3-3 inches. 



Shell lanceolate, very transverse, very inequilateral, rounded before 

 and very acutely angular behind, irregularly folded in the region of 

 the beaks, several larger folds on the anterior slope, on the poste- 

 rior portion the folds are parallel being nearly perpendicular to the 

 basal margi;i, flattened on the sides ; umbonial slope elevated into a 

 ridge, green ; substance of the shell thin ; beaks depressed, placed very 

 near to the anterior margin ; ligament thin, not very long ; epidermis 

 finely wrinkled, yellowish with obsolete rays, disposed to be greenish 



