124 PALEONTOLOGY OF NEW JERSEY. 
The species was originally described from Prairie Bluff, Alabama, where 
the specimens are of large size and sometimes show evidences of the shell, 
which must have been of considerable thickness, as they are frequently seen 
to have been perforated by a boring sponge. The New Jersey casts differ 
from those of G. infracarnita Gabb, with which this species is usually con- 
founded, in being less oblique, more erect, lower in the spire, the volutions 
rounder and not carinate on the edge of the wide umbilicus. The evidence 
of its relations to the genus Gyrodes is not very strong. 
formation and locality: In the ferruginous layers of the Lower Marls 
at Mullica Hill, and near Burlington, New Jersey, not a very common 
species; also from the same position at Tinton Falls, New Jersey. Col- 
lection at Columbia College. 
Genus GYRODES Conrad. 
GYRODES ABBOTTII. 
Plate xv, Fig..17. 
Gyrodes Abbotti: Gabb : Proc. Acad. Nat. Sci.. Phila., 1861, p. 320 ; Meek, Check 
List Cret. and Jur. Foss., p. 21; Geol. N. J., Newark, 1868, p. 729. 
This species was described by Mr. Gabb froma single individual cast, 
which retains around the summit of the outer volution remains of markings 
which present the appearance of a series of undulations, or “oblique plica- 
tions,” having a backward direction in their passage from the suture line 
across the body of the shell. Aside from these markings there is not the 
slightest difference between this and the ordinary casts of G@. abyssinus Mor- 
ton, either in form or bulk. The specimen is preserved in a ferruginous 
gravel or very coarse iron sand, which fills the sutures and umbilical cavity, 
and toa considerable extent obscures these features; so that a striet com- 
parison is not possible without changing its appearance by clearing away the 
adhering material. This I have not ventured to do, as the specimen is the 
property of the Acad. Nat. Sci., Phila, and the change would destroy the 
features upon which the author of the species founded it, which I do not 
consider I have the right to do. . I do not think, however, the species is a 
valid one, but regard it as only an accidental form of Gyrodes abyssinus. If 
the adhering material were cleaned away, I think the cast beneath would 
