952 ZOOLOGY— MOLLUSOA. 



ADDENDA. 



ANODONTA DEJECTA, Lewis. 

 In 1874, a new and interesting- species was discovered and submitted 

 to Dr. Jarnes Lewis, of Mohawk, N. Y., who has kindly furnished the 

 description given in the following addenda: — 



"Description of a new species ofAnodonta, by James Lewis, Mohawk, N. Y., 



May 27, 1875. 



"ANODONTA DEJECTA, sp. nov. 



"Shell obovate, subcylindrical, inequilateral, slightly disposed to be alate 

 posteriorly, emarginate on the base, posteriorly dilated and somewhat 

 broadly triangular ; substance of the shell of moderate thickness, and dis- 

 posed to be opaque ; beaks scarcely elevated above the dorsal margin, hav- 

 ing a few minute, irregular undulations at their tips ; ligament somewhat 

 long ; epidermis yellowish-brown or olivaceous, polished, and without rays ; 

 lines of growth coarse and somewhat distant ; anterior cicatrices distinct ; 

 posterior cicatrices confluent ; dorsal cicatrices in the cavity of the beak a 

 little removed from the dorsal margin, which is slightly arcuate ; nacre 

 white or faintly tinted salmon-color and iridescent. 



"Transverse diameter, 2.90 inches; altitude, 1.35 inches; lateral 

 diameter, 1 inch. 



" Found in Arkansas River or its tributaries west of the one hundredth 

 meridian, by Dr. H. C. Yarrow, surgeon and zoologist to expedition for 

 exploration west of the one-hundredth meridan. 



" National Museum, Smithsonian Institution. 



" A number of shells taken west of the one hundredth meridian were 

 sent to me for identification a short time ago, and among them were speci- 

 mens of the above described Anodonta, which appeared to me to be new, and 

 I referred Dr. Yarrow to Mr. Lea, who requested that the shells be sent back 

 to me for description. The specimens consist of one imperfect shell and 

 fragments of others. 



"The most perfect specimen is slightly abnormal, but presents features 

 which are unquestionably characteristic, as they are also indicated in the 

 other (fragmentary) specimens. The form of the shell is somewhat like 



