AND DESCRIPTIONS OF NEW SPECIES. 95 



Unio C^ruleus. Plate XIII. fig. 25. 



Testa angusto-ellipticd, transversa, inmquilaterali, subcylindraced; valvuKs ten- 

 uibits; natibiis prominulis, rotundatis et undulatis; dentibus cardinalibus lamelli- 

 formibus, et in dextrA valvuld sold duplicibus; lateralibus rectis; margaritd cceru- 

 leo-albd et iridescente. 



Shell narrow-elliptical, transverse, inequilateral, subcylindrical; valves thin ; beaks 

 rather elevated, rounded and undulated; cardinal teeth lamelliform and double in 

 the right valve only ; lateral teeth straight ; nacre bluish white, pearly and irides- 

 cent. 



Hab. River Hoogly, Hindostan, G. W. Blakie. 



My Cabinet. 

 Cabinet of G. W. Blakie. 

 Cabinet of Professor Vanuxem. 

 Cabinet of P. H. Nicklin. 

 Cabinet of H. C. Carey. 

 Cabinet of the Academy of Natural Sciences of Philadelphia. 

 Cabinet of Dr Burrough. 

 Diam. -6, Length -8, Breadth 1-6 inches. 



Shell narrow-elliptical, transverse, subcylindrical, disposed to be 

 straight on the sides and basal margin ; substance of the shell thin ; beaks 

 near the anterior margin rounded, somewhat elevated, and corrugated 

 with diverging undulations ; ligament rather short and straight : epi- 

 dermis finely wrinkled and bluish green, particularly on the posterior 

 part; rays very indistinct; posterior slope furnished with small undu- 

 lations and two irregular rays on each side ; cardinal teeth lamelliform 

 and double in the right valve only; lateral teeth straight and lamelli- 

 form; anterior cicatrices distinct ; posterior cicatrices confluent; dor- 

 sal cicatrices within the cavity of the beaks; cavity of the beaks 

 wide and rounded ; nacre bluish white, very pearly and iridescent. 



Remarks. — This species was brought from Calcutta by Mr Blakie, 

 to whose kindness I am indebted for it and many other fine shells. 



