64 DESCRIPTION OF NEW 



Anodonta decora. Plate XX. fig. 63. 



Testa elliptica, incequilaterali, valdh infiata ; valvulis tenuibus ; natibus prominulis, ad 

 apices undulatis ; epidermide glabra, una vittala; margarita alba, salmonis colore tinctd. 



Shell elliptical, inequilateral, very much inflated ; valves ihin ; beaks somewhat pro- 

 minent and undulated at the tip ; epidermis smooth and single banded ; nacre while 

 and salmon colour. 



Hab. Canal near Cincinnati, Ohio. T. G. Lea. 

 Canal near Chilicothe, Ohio. Dr Ward. 

 My Cabinet. 

 Cabinet of T. G. Lea. 

 Cabinet of Dr Ward. 

 Cabinet of Mr Hyde. 

 Diam. 1-8, Length 2-5, Breadth 3-9 inches. 



Shell elliptical, nearly straight on the dorsal margin, subangular be- 

 hind, inequilateral, very much inflated ; substance of the shell thin ; 

 beaks rather prominent, and undulated in a double series at the tip; 

 ligament rather long and straight; epidermis smooth and shining, fur- 

 nished with green rays beyond the dark transverse band situated about 

 the middle of the valve ; posterior slope dark, with three rays on each 

 valve ; anterior cicatrices confluent ; posterior cicatrices confluent ; dor- 

 sal cicatrices situated in the centre of the cavity of the beaks ; cavity 

 of the shell deep ; cavity of the beaks rather small ; nacre slightly 

 salmon-coloured in the cavity, and white on the remaining portion. 



Remarks. — My brother, T. G. Lea, called my attention some years 

 ago to this shell. It, however, so nearly resembled A. plana (nobis), 

 that I was disposed to consider it only a variety of that species. A re- 

 markably fine suite, however, recently received from Dr Ward, has satis- 

 fied me that it ought to be separated from it. Indeed these specimens 

 are so much inflated, as to have induced Dr Ward to suppose they might 

 belong to An. Stewartiana (nobis). The broad and distinct band which 

 in adults transversely crosses the valve about half way between the beak 

 and the margin, is very remarkable in this species. This band defines 



