402 



PROCEEDINGS OF THE ACADEMY OF 



[Part II 



Specimens of this species were found in the mud washed out of 

 Cymatium praefemorale, no. 3222. 



LEDIDAE. 



Leda extricata Pils. and Johns. Plate XXXVIII. figs, l, la. 

 Proc. A. N. S. Phila., 1917, p. 185. 



Yoldia ovalis Gabb. Text-flg. 34. 



Yoldia ovalis Gabb, Trans. Amer. Philos. Soc, xv, 1873, p. 255. ' 



Externally there are some low concentric wrinkles in the lower 

 half of the otherwise smooth valve. Length 8 2, alt. 4.5, diam. of 

 one valve 1.5 mm. 



Type no. 3319, a single left valve. 



Fig. 34. Yoldia ovalis Gabb, Type. 

 LIMOPSIDAE. 



Limopsis ovalis Gabb. Text-flg. 35. 



Limopsis ovalis Gabb, Trans. Amer. Philos. Soc, xv, 1873, p. 255. 



The sculpture consists of many fine thread-like radii and much 



Fig. 35. Limopsis ovalis Gabb. 



more prominent and coarser, unequal concentric wrinkles, 

 hinge has 8 teeth on each side of the median hiatus. 



Length 9, alt. 9.7, semidiam. 2.5 mm. (Type). 



Type is no. 2657 A. N. S. P. 



The 



