372 CRETACEOUS PALEONTOLOGY. 



anterior margin rounded ; antero-dorsal margin sloping some- 

 what abruptly from the beak. Hinge-line with 20 to 25 teeth 

 posterior to the beak and 10 or 12 in front, with a few small 

 ones directly beneath the beak. Surface of the shell marked by 

 somewhat regular concentric lines. Surface of the casts usually 

 smooth and without marginal crenulations. 



The dimensions of a rather large individual from the Weno- 

 nah sand are: length, 21 mm; height, 15.5 mm. 



Remarks. This species was at first identified as Nucula mon- 

 mouthensis Whitf., but a study of Whitfield's type of that species 

 has shown it to be a member of the genus Lima. A second speci- 

 men, in the collection of the Philadelphia Academy of Science 

 which was referred by Whitfield to his N. monmouthensis, is 

 apparently identical with the shells here described. The species 

 differs from N. percrassa in the absence of radiating costse upon 

 the external surface of the shell, and in the absence of marginal 

 crenulations. 



Formation and locality. Cliffwood clay, Cliffwood Point 

 (105); Merchantville clay-marl, near Matawan (ioi 2 ), near 

 Jamesburg (140), Lenola (163); Woodbury clay, Lorillard 

 (102), near Matawan (103), near Haddonfield (183), Cross- 

 wicks (168); Wenonah sand, near Crawfords Corner (i26 3 ), 

 near Marlboro (130) ; Red Bank sand, near Middletown (112), 

 Red Bank (119). 



Geographic distribution. New- Jersey. 



Family LEDIDAE. 



Genus LEDA Schumacher. 



Leda compressifrons (Whitfield). 



Plate XXIX., Figs. 13-17. 



1886. Nuculana compressifrons Whitf., Pal. N. J., vol. i 

 (Monog. U. S. G. S., vol. 9), p. 109, pi. n, fig. 9. 



Description. Shell small, the dimensions of an average speci- 

 men from Lorillard being: length, 8.5 mm., height 4 mm. 

 Beaks rather prominent, situated near the anterior third of the 



