1 04 PALAEONTOLOGY OF NEW JERSEY. 



scar as seen on the internal cast large and distinct on the anterior end, less 

 strongly so on the posterior. Teeth strong on the posterior side and grad- 

 ually decreasing toward the beak; twenty may be counted on the cast 

 figured. Those of the anterior side not seen. Margin strongly and deeply 

 crenulate. Surface of the shell marked with fine radiating striae, which are 

 but faintly marked on the body of tlie valve, but are much more strongly 

 developed near the margin, meeting the crenulations of the edge of the 

 shell so as to deeply indent the border. Also by strong concentric lines of 

 growth. Internal structure of the shell strongly fibrous. 



Mr. Gabb remarks, on page 318, Proc. A. N. S., Phil., 1876, that he 

 has 'kittle doubt this will prove to be identical with N, percrassus,^'^ a 

 species, previously described, from Patula Creek, Georgia ; a form mucli 

 larger and of a slightly different shape. I think it extremely doubtful if 

 this opinion be correct, however, for according to the figure of that species, 

 it is much more triangular in form than this one. On account of which 

 difference, in the absence of Authentic specimens of that species with which 

 to compare, I should prefer to consider them as distinct.- There can be no 

 doubt about the generic relations of this shell, as the form is entirely unlike 

 that of Leda and Nuculana. 



Formation and locality, — In tlie micaceous clays, under the Lower Marl 

 Bed, at the Rev. G. C. Schanck^s pits, near Marlborough, New Jersey. Mr. 

 Gabb's specimens were from Crosswicks, New Jersey. 



Nucula perequalis. 



Nticiila pereqtialis Conrad. J. A. N. Sci., Phil., new ser., Vol. lY, p. 281. Meek, Geol. 

 Eept. K. J., 1868, p. 725. 



Mr. Conrad describes 1;his species as follows: ^^Triangular, rather elon- 

 gated, equilateral, ventricose; dorsal margins equally declining; end mar- 

 gins acutely and equally rounded; basal margins regularly rounded.^' The 

 locality given is Eufaula, Barbour County, Alabama. 



Mr. Meek cites this as a New Jersey species in his list given in the 

 Geological Report for 1868, p. 725. I have not been able to find Mr. Con- 

 rad's type specimen, and as he did not figure it, it is nearly impossible to 

 identify a form of this character from so imperfect a description. More- 

 over, as the species was originally described from a Southern locality, I 



