GASTEROPODA OF THE LOWER GREEN MARLS. 65 
FASCIOLARITDA. 
ODONTOFUSUS, new genus. 
Shell univalve, fusiform, resembling Fusus or Fasciolaria in general 
appearance; spire elevated, with vertically plicated whorls; anterior extrem- 
ity prolonged into a straight canal of greater or less extent; columella 
marked near or above the middle by a single oblique fold; surface probably 
lirated, although no evidence of such a feature remains on the casts. 
Types 0. (Fasciolaria) Slacki Gabb and O. typicus Whitt. 
I am compelled to propose a new generic name for a group of species 
possessing the above characters, although reluctant to do so on internal 
casts. ‘he specimens closely resemble specimens of Fusus or Fasciolaria 
in their elongated fusiform character and prominent volutions, which have 
been strongly marked by vertical folds; but they differ from either in the 
characters of the columellar ridge or fold. From Fusus they differ in its 
presence and in the straight beak, and from the other in having only a 
single ridge, which is placed much higher on the columella. Mr. Gabb 
noticed the ridge on the columella in his original description of F. Slacki, 
and in some later remarks' he suggests its relation to Piestochilus Meek. 
Mr. Meek’s genus usually possesses more than one fold, but differs very 
materially in the characters of the spire and the more elongated anterior 
beak. In fact, Piestochilus more closely resembles Mitra than Fasciolaria. 
The shells referred to Borsonia and Cordicria also somewhat resemble 
these, but possess a distinct sinus in the lip like Plewrotoma and are shorter 
in front as well as having denticulations on the inside of the outer lip, 
features which these shells have not possessed. It is somewhat uncertain 
whether there have been spiral striz on the shell, no evidence of such 
feature being present on any of the many casts examined. In general 
features the genus resembles somewhat Cordiera A. Rouault, but there is no 
evidence of a sinus or slit in the lip allying it to Pleurotoma, as in that one. 
Cordiera is from the Eocene in Europe. 
| ' Proc. Acad. Nat. Sci., Phila., 1876, p. 282. 
MON XVIII-——9) 
