48 PALEONTOLOGY OF NEW JERSEY. 
of the anterior beak, as a part of the marl has crumbled at that pomt, 
but as far as the specimen showed when first obtained, the figure is cor- 
rect and may be relied upon. The specimen is, moreover, somewhat dis- 
torted by oblique pressure, making the under surface of the volution broader 
and less abrupt than is natural. This corrected would cause it to resemble 
Mr. Gabb’s figure more closely. 
Formation and locality: In the dark-green, friable, and rather coarse 
layers of the Lower Green Marl, at Holmdel, New Jersey. In the collee- 
tion of Prof. Reiley. Mr. Gabb’s specimen was from Mullica Hill, New 
Jersey, from a similar position. 
Genus PYRIFUSUS Conrad. 
Jour. Acad. Nat. Sci., Phila., 2d ser., vol. 3, 1858, p. 332. Type P. subdensatus, 
ibid, p. 332, Pl. xxxv, Fig. 12. 
Mr. Conrad describes this genus, which is founded upon his species 
Pyrifusus subdensatus, as follows: “Pyriform; columella broad, thick, flat- 
tened; body volution transversely oval.” Mr. Conrad’s type specimen upon 
which both the species and the genus was founded is before me, and there 
are two of the characters as given in the above generic description that I 
should consider as not really belonging to the shell. The statement that 
the columella is “flattened,” I should consider incorrect. It is excessively 
thickened for the entire length of the inner lip, almost forming a tubercle 
at the upper end, and along the narrow part of the canal is so much thick- 
ened as to give it a sharply angular ridge on the inner edge, but there is no 
flattening of the columella like that of Littorina or Purpurea. In this one 
specimen, the only one I have seen of the species, the thickening of the 
columella with age has been so great as to raise its surface very much above 
that of the external shell surface directly against it, in this way making 
the entire columella much broader than it would be in a younger shell. 
Another feature of the description above quoted is “body volution trans- 
versely oval.” Nearly all univalve shells having rapidly increasing volu- 
tions appear oval in a summit view, or, as the description says, “transversely 
oval,” from the greater increase in diameter of the outer part of the volu- 
