160 AMERICAN JOURNAL 



Dimensions. — Diameter 1^ in cli; length 3 inches; breadth 

 If inches. 



Habitat. — Shears Lake, Michigan. 



My Cabinet. Cabinet of Hugh Cuming, London. Mus. 

 Comp. Zoology, Cambridge, Mass. Cabinet of George W. 

 Tryon, Jr. 



Observations. — Its fine, translucent, yellow epidermis, to- 

 gether with its inflated form, will readily determine this spe- 

 cies. It is extremely delicate in texture for so large a shell, 

 and one evidently adult. Only three or four specimens have 

 come under notice, but they all have the peculiar characters, 

 and it is manifestly not the young of any other species. 

 Anod. pallida, nob., herein described, is, perhaps, equally 

 delicate ; but tlie yellow color of that species is relieved by 

 the green tinge near its base, and it is much more depressed. 

 Other species may resemble this in some of its characters, but 

 it seems to be peculiar in its soft, creamy white, diaphanous 

 epidermis, and delicately rounded outline. * 



Anodon flay a, Anthony. — t. 14, f. 3. 



Description. — Shell, smooth, thin, elliptical, very inequilate- 

 ral; epidermis light brownish-yellow, very obscurely rayed; 

 beaks slightly raised, and undulated at the tips ; hinge-margin 

 very straight ; ligament rather short and thin ; marks of growth 

 distinct and distant, about three on each valve; anterior and 

 posterior cicatrices scarcely perceptible; nacre silvery white and 

 iridescent. 



Habitat. — Michigan, 



My Cabinet. Cabinet of Hugh Cuming, London. Mus. 

 Comp. Zoology, Cambridge, Mass. 



Observations. — Distinguished by its fine, soft, yellowish 

 color, which is very opaque, looking as if painted on the shell ; 

 surface very plainly and closely concentrically striate; resem- 

 bles Anod. pallida, nob, in form, but is less slender, thicker, 

 and has the marks of growth more crowded and darker co- 

 lored, besides being a rougher and more ventricose species. 



Anodon sub-inflata, Anthony. — t. 15, f. 1. 



Description. — Shell long-ovate, much inflated, somewhat 

 gibbous, very inequilateral ; substance of the shell rather 

 thick; beaks prominent, undulate at tip ; epidermis olivaceous 

 over the umbones and on the anterior portion of the shell, 

 while its posterior end is darker, and even of a brownish 

 tinge ; marks of growth very distant and distinct, about three 

 on each valve ; dorsal line yqyj straight ; nacre silvery white 

 and iridescent. 



