The Productivity of Fish Food in Oneida Lake 247 



DESCRIPTION OF A NEW VARIETY OF FRESH- 

 WATER MUSSEL FROM ONEIDA LAKE, N. Y. 



By Frank C. Baker 



The New York State College of Forestry, at Syracuse University, 

 Syracuse, N. Y. 



Lampsilis radiata oneidensis F. C. Baker (Baker '16, fig. 44, 

 Nos. I, 3, 4). 



Shell elliptical in outline, rounded at both ends, somewhat 

 compressed; dorsal margin slightly curved, ventral margin 

 rounded, notably so in the male shell ; female shell produced 

 postbasally; surface usually roughened by growth lines, rarel)' 

 smooth; epidermis olive-green, the posterior half usually black 

 or brown, obscuring the markings; a few dark green rays of 

 the radiata type are present on some shells ; umbones promi- 

 nent, inflated, but little elevated above the contour of the 

 dorsal margin ; umbonal slopes rounded ; cardinal teeth of 

 the left valve double, rather heavy, seiTated, the anterior car- 

 dinal higher than the posterior and pyramidal in shape, the 

 posterior cardinal rectangular, somewhat compressed; the pit 

 at the base of the anterior cardhial teeth is deep and wide; 

 there is a small narrow pit at the base of the anterior cardinal 

 teeth; cardinal teeth of right valve two in number, triangular, 

 the anterior small, compressed, the posterior large, elevated 

 above the anterior, forming a truncated pyramid; the pit 

 between the teeth is narrow and deep; the anterior cardinal 

 of this valve is reduced to a mere remnant in some individuals; 

 the ridge joining the cardinal and lateral teeth is heavy and 

 bears one or more tubercles ; lateral teeth as in radiata; anterior 

 adductor muscle scar, posterior adductor muscle scar, and 

 dorsal muscle scar more heavily impressed than in radiata; 

 nacre bluish-white, slight irridescent. 



Length Hcighth Breadth Type 



56 36 21 mm. No. 211 h, a single specimen. 



52 35 20 mm. No. 211 i, from the type lot. 



52 27 20 mm. No. 211 j, from the type lot. 



