162 AMERICAN JOURNAL 



Anodon pallida, Anthony, — t. 15, f. 3. 



Description. — Shell smooth, elliptical, thin, rounded before, 

 biangular behind, and very inequilateral; epidermis pale yel- 

 low, with faint and fine green rays over the whole disc, which, 

 being more numerous and crowded on the posterior part of 

 the shell, gives it a decided green tinge near its lower mar- 

 gin ; substance of the shell exceedingly thin, and very trans- 

 parent; beaks slightly prominent, finely and closely undu- 

 late at the tips, having about ten waved wrinkles on the first 

 growth; ligament rather short, pale in color, and very slender; 

 posterior and anterior cicatrices very slightly impressed, be- 

 ing scarcely visible; nacre silvery white and very iridescent. 



Dimensions. — Diameter | inch; length 3 inches; breadth 

 IJ inches. 



Habitat. — Michigan. 



My Cabinet. Cabinet of Hugh Cuming, London. Cabinet 

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

 W. Tryon, Jr. 



Observations. — Cannot well be compared with any known 

 species. Its pale, delicate coloring and beautifully undulated 

 beaks will serve to identify the species ; and its well defined 

 and very distant lines of growth are also unusual in this 

 genus. Rarely do we find more than two on each valve, and 

 being quite dark, they contrast finely with the general color 

 of the shell. In the regularity and beauty of the undulations 

 on its beak, I have seen no species comparable with it, ex- 

 cept, perhaps, A7iod. opalina, herein described, and that species 

 resembles this, also, in general tone of coloring, but is shorter, 

 more inflated, and has not any of the green tinge so charac- 

 teristic of Anodon pallida. 



Anodon micans, Anthony. — 1. 16, f 1. 



Description. — Shell smooth, elliptical, and very inequilateral ; 

 substance of the shell thin ; epidermis brownish-olive, wrink- 

 led or striate; beaks flattened, not prominent, and with 

 apparently few, if any undulations at tip; shell not much 

 inflated, rounded before and more depressed, and broadly, 

 but not very distinctly biangular behind; anterior cicatrices 

 distinct and well impressed; posterior cicatrices confluent; 

 nacre of a brownish golden color over the whole interior, and 

 very iridescent. 



Dimensions. — Diameter 1 inch; length 2f inches; breadth 

 If inch. 



Habitat. — Texas, 



My Cabinet. 



