102 PALAEONTOLOGY OF NEW JERSEY. 



NUCULID^.. 



Genus NUCULA Lam. 

 Nucula percrassa. 



Plate XI, Figs. 4-6. 



Nucula percrassa Conrad. Jour. A. N. S., new ser., Vol. Ill, p. 327, PI, XXX Y, Fig. 4. 

 Gabb, Synop., p. 149. Meek, Check-list, p. 8. Geol. Surr. N. J., 1868, p. 725. 

 N. percrassa Gabb. Proc. A. N. Sci., PLil., 1876, p. 318. 



A single cast of this species occurs in the collections of the A. N. S., 

 Phil., sent to me in a tray with two specimens of Cibota uniopsis Con., from 

 New Jersey, and probably from near Burlington, but without distinctive 

 mark, either as to species or locality. The lithological featui'es of it are 

 quite diflferent from those of the Cibota in the tray, and I presume it to be 

 from Haddoufield or in that vicinity. The species has been recognized by 

 several authors as coming from New Jersey, and consequently I have 

 figui'ed this specimen as presumably from within the State. 



The cast is more elongate than any of those of N. Slackiana Gabb, the 

 nearest allied form, and the shell has been more thickened. The cast is 

 about as long again as high, with very large projecting beaks, which are 

 situated at about the anterior third of the length. The muscular scars are 

 very strong, and the pallial line very well marked. The teeth, as indicated 

 on the cast, have been quite numerous, and extend on the posterior side to 

 the muscular scars, but are obliterated on the anterior side. The ligament 

 pit is well marked, but not prominent. No markings of the exterior are 

 preserved, the shell having been too thick to transmit them. 



The shell has been proportionally moi-e elongate than N. Slackiana^ 

 while nearl}' of the same height, and the beaks, I should judge, were farther 

 removed from the anterior end. I think the species quite distinct from that 

 one, and well worthy of being retained as valid. 



Nucula Moumouthensis, u. sp. 

 Plate XI, Fig. 1. 



Shell rather below a mediimi size, triangularly ovate, with convex 

 valves and sharp, pointed beaks, which are even with the anterior end of 



