360 TA. Conrad on American Fossiliferous Strata. 
List of Shells of the Crosswicks Group. 
Crassatella prora Conrad. Gyrodes infracarinata Gabb. 
Lnoceramus peculiaris C, Natica (Lunatia?) obtusevolva Gabb. 
rigonoarca passa C, Turbinopsis depressa 
rosoma inflata C. Acton ovoidea 
Cyprimeria spissa C. Acteon cretacea Gab 
Axinea Mortoni C. Baculites vetus Conrad.* 
Nuculana Slackii Gabb. Scaphites hippocrepis Dekay. 
Solenoceras annulifer (Hamites) Morton. 
Raritan Cuay. 
In his report on the geology of New Jersey, Professor Rogers 
describes a series of clays on the Delaware and Raritan riv- 
ers, which he considers the base of the Cretaceous system 
be the equivalent of the Wealden of Europe, but I think 
it is of later origin ; posterior to the lower greensand, and 
indicating a continent, which disappeared beneath the cre- 
tide. This lower bed is about four feet thick near Washing- 
ton, and over it is a like thickness of black clay, the upper 
etek willow shaped leaves with an entire margin, Over 
eplete with ‘similar leay ; ions of 
other SO Fe od nok eaves and also vegetable impress 
t. Durand informs me that a fra ent of one of the leaves 
from this clay, is that of a fern, the Fats on which represent 
the fructification of the plant. These leaves are abundant in 
_ _* This Baculite has istan han B. 
ovatus. I have as yet bots gall fare _ res lobed septa than 
