2A PALEONTOLOGY OF NEW JERSEY. 
Shells obtained from New Jersey and known only by the upper valves, 
small, scarcely exceeding half an inch in diameter, subcircular in outline, 
usually very little longer than wide and broadest below the middle of the 
length. Usually, however, somewhat irregular. Apex of the dorsal valve 
‘ather elevated and obtusely pointed, situated at about one-fourth of the 
whole diameter from the dorsal margin. Surface of the shell strongly 
lamellose over the outer half of most specimens and often to near the 
apex. In most cases, however, the apex and umbo are smooth and_pol- 
ished, except for the very fine radiating lines which are visible under a 
glass over much of the surface under the lamella, or show on the expan- 
sions as wrinkles, most especially on the short side of the apex. The sub- 
stance of the shell is thick and entirely corneous, and the muscular scars 
on the inside usually well marked. 
Localities: I have received specimens only from near Shiloh and 
Bridgeton, N. J, both from the collections at Rutgers College and from the 
National Museum 
