368 Review of some recent American 
Of the more characteristic Cretaceous types, 111 species of 
Ammonitidx, 40 of Inoceraminzx, 9 of Venilia, 8 of Gryphea, 7 
of Neithea, and 19 of Rudista, &c., are enumerated, and 13 new gen- 
era or subgenera are established for Cretaceous forms. Amon 
observations on other types, is one especially deserving considera- 
tion from naturalists; ‘it is not probable that any of the species 
retained under the name Fusus in the foregoing list, belong to 
that genus” as properly restricted. Apparently few of the species 
indeed belong to the same family (Fasciolariide) with the true 
Fusi or Coli, some belonging rather to the Buccinidz and others 
with the Cassidulidw, &. The mollusca possessing shells of a 
more or less subfusiform shape require a severe revision by one 
conversant with the anatomy of the including order; congeneric 
species have been widely separated from each other, while very 
diverse types have been combined under one genus, and from 
this defect the latest works have been by no means free. 
The Eocene strata are grouped by Mr. Conrad under three 
sections—the “Lower and Medial Eocene (Shark River and 
Group: the three groups are believed to hold “ few if any spe- 
cies in common.” Of the 
r an examination of almost all the 
ving species of the latter, the conclusion has been forced on us 
that the species in question is more nearly related to the P. fieus 
than several of the species that no one has pretended to at all 
isolate; yet it is not only generically separated by Mr. Conrad 
* The name Pyrula (Lam. 1799 type Bulla ficus L.) is provisionally ado} 
rather than Sycotypus or Ficus: Rpts, in the first shins i wet congeneric with 
Farule, but was tased on Busyoom conaliculateen or pyrum, and Browne's sees 
being binomial, can rcely be adopted. Ficus is objectionable, as name 
had previously been used in botany. ied wes 
