NIAGARA FALLS AND VICINITY 249 



Shell large, oblong, ovate, compressed and comparatively thin; 

 surface regularly and smoothly marked by growth lines; anterior 

 end rounded, posterior end slightly angulated; dorsal margins 

 straight or nearly so, hollowed a little back of the beaks; ventral 

 margin straight; adductor muscle impressions well defined; cardinal 

 teeth not large, two on the left valve and one on the right; lateral 

 teeth delicate; beak, in present specimen, smooth, slightly sculptured 

 in recent specimens. 



Locality. Goat island. 



Lampsilis ellipsiformis (Conrad) Simpson 1900 (Fig. 185). 

 Unio ellipsiformis Conrad (1836. Monograph, 8 :6o) 

 Unio spathulatus Lea (1845. Am. philos. soc. Proc. 4:164) 

 Lampsilis ellipsiformis Simpson (1900. U. S. not. mus. 

 Proc. 22:557) 



Shell oblong, very compressed, rounded both anteriorly and pos- 

 teriorly; surface slightly roughened by the growth lines; dorsal 



/ 



Fig. 185 Lampsilis ellipsiformis 



margins curved; ventral margins angulated toward the posterior 

 end; anterior adductor muscle impression deep and triangular, 

 slightly pitted; posterior muscle scar broad and oval, showing the. 

 ray-like growth lines; hinge area broad and flat; teeth strong, 

 both cardinal and lateral, there being two cardinal teeth in each 

 valve, two lateral teeth in the left valve and one in the right; hinge 

 area between the cardinal and lateral teeth broad and very slightly 

 undulated; pallial line well impressed; beaks low, showing no' sculp- 

 ture, though recent specimens show delicate waves or ridges. 



Locality. Found in Prospect park by Prof. Irving P. Bishop. 



