830 KANSAS UNIVERSITY SCIENCE BULLETIN. 



Anodontoides ferussacianus Lea. Plate LXXIV, fig. 2. 



Anodontoides ferussacianus Lea, Trans. Amer. Phil. Soc. , v, 1834, p. 

 45, pi. VI, fig. 15. 



Shell of moderate size, elliptical, narrowing posteriorly, 

 thin, slightly inflated. Anterior margin fully rounded ; ven- 

 tral decidedly bowed, sometimes a little incurved centrally ; 

 posterior margin roundly pointed, dorsal margin straight to 

 slightly curved. Umbones of moderate height and inflation, 

 and ornamented with several ridges, which are bluntly pointed 

 posteriorly. Anterior and lateral umboidal slopes fully 

 rounded ; posterior slope often slightly excavated near the 

 dorsal margin. Epidermis smooth and shining, of dark 

 olive-green or brown, lightest over the umbones, and often 

 ornamented with wide, rather obscure dark green rays. 

 Lines of growth dark and continuous, but not generally im- 

 bricated or roughened. Ligament weak and light brown in 

 color. 



Interior : Hinge line slightly thickened, slightly incurved 

 in front of the beaks, and sometimes showing a slight rudi- 

 ment of a pseudocardinal. Muscle scars fairly well outlined, 

 large, the anterior scars distinct, the posterior scars confluent. 

 Pallial line outlined for its entire length. Cavity of the shell 

 large, of the beaks slight. Nacre white or bluish, slightly 

 iridescent. 



Length. Height. Breadth. Dm. ra. 



75 37 22 0.30 (Coll. W. C.) 



This species is found throughout the Mississippi drainage 

 and in a number of rivers of eastern Canada. In Kansas it 

 has been reported only from the northern or Kansas drainage. 

 In this area we have a series of reports extending from the 

 eastern boundary of the state west to Sappa creek, near 

 Oberlin. Call (5.) This is the extreme western range of the 

 Kansas Unionidse as at present reported. 



When young this species is easily identified by its bright 

 green shell and striking rays, but the older shells lose these 

 characters. It may be separated from Anodonta grandis by 

 its more pointed beaks, cylindrical shell, and gradually pointed 

 posterior margin. This last is not always constant. 



