MOLLUSCA. 373 



shell. Posterior portion of the shell, from the beaks back, sub- 

 cuneate in outline, the posterior extremity sharply rounded, and 

 just below the extremity the margin is very obliquely subtruncate 

 for a short distance; anterior portion of the shell in front of the 

 beaks subsemielliptical in outline. Hinge-line elongate, the 

 anterior and posterior portions widely divergent, meeting under 

 the beak at an angle of about 140, the posterior row of teeth, 

 20 or more in number, the anterior row with about 12 or more 

 teeth. External surface of the shell, as indicated by impressions, 

 perfectly smooth. 



Remarks. This name was first legitimately used by Whitfield, 

 although that author credits it to Conrad. Conrad, however, 

 only applied it as a manuscript name upon a label in the collec- 

 tions of the Philadelphia Academy of Science, and it was never 

 actually published prior to the appearance of Whitfield's mono- 

 graph. The shells occur commonly in the collection from Had- 

 donfield, from which locality the species was originally de- 

 scribed, and also in the same formation in other portions of the 

 State. Whitfield's original illustration of the species is inaccu- 

 rate in representing the posterior extremity of the shell too 

 squarely truncate. In this character the original specimens from 

 Haddonfield resemble those here illustrated from Lorillard, but 

 the Haddonfield examples are usually a little more pointed than 

 those from Lorillard, a difference which may be due to the 

 difference in the conditions of preservation of the species at the 

 two localities. 



Formation and locality. Merchantville clay-marl, near James- 

 burg (139, 140, 141); Woodbury clay, Lorillard (102), Cross- 

 wicks (168), near Haddonfield (183, 165). 



Geographic distribution. New Jersey. 



Leda pinnaformis Gabb. 

 Plate XXIX., Fig. 27. 



1860. Leda pinna forma Gabb, Jour. Acad. Nat. Sci. Phil., 2d 



sen, vol. 4, p. 303, pi. 48, fig. 22. 



1861. Leda pinnaeformis Gabb, Synop. Moll. Cret. Form., p. 



189 (133). 



