^8 AMERICAN JOURNAL 



TRIGONARCA, Conrad. 

 T. CUNEIFORMIS, Conrad. — PL 9, fig. 1. 



Description. Trapeziform, inequilateral, elongated, posterior 

 side cuneate ; anterior side distinctly radiated ; posterior radii 

 very minute, close, obsolete ; umbonal slope angulated ; post 

 umbonal area depressed, extremity acute ; posterior hinge mar- 

 gin oblique. 



Locality. Haddonfield, N. J. 



The smallest species yet known. 



PERRISONOTA, Conrad. 



Equivalved, elongated ; posterior hinge line long, curved, lin- 

 ear, with numerous close, transverse teeth, extending nearly to 

 the end margin ; anterior hinge area broad, oblique and some- 

 what distant from the hinge margin. No fosset under the apex ? 



P. PROTEXTA, Conrad. — PI. 9, fig. 24. 



Description. Subensiform, smooth, convex; anterior side 

 short, extremity situated nearer the hinge than ventral margin. 



Locality. — Haddonfield, N. J. 



NUCULARIA, Conrad. 



N. PAPYRiA, Conrad. — PI. 9, fig. 25. 



For description see p. 4-1 of this work. The figure represents 

 a larger specimen, with some variation of form from that on pl. 

 1, fig. 7. 



Locality. — Haddonfield, N, J. 



CYPRIMERIA, Conrad. 



C. CRETACEA, Conrad. — PI. 9, fig. 12. 



Dosinia Haddonfieldensis, Lea., Proc. Acad. Nat. Sci. 1861, 

 p. 149. 



This is the only species yet found at Haddonfield, where it is 

 abundant. Young shells are distinctly sculptured over the 

 whole disk with regular concentric lines, but the adult has them 

 only on the umbo, the other lines being those of growth. This 

 species is distinguished by its obtuse front margin, and the ele- 

 vated or less oblique hinge margins, compared with O. depressa, 

 Conrad. The figure in the Journal of the Academy represents 

 the interior ; the disk is here figured together with the hinge. 



