1 68 
The American Geologist. 
September, 1905 
is indicated by its thinning to the eastward and the absence 
of the two upper fossil beds which are present in the 
western part. 
The character of the beds renders them easily eroded 
and the exposures are constantly changing owing to the un- 
dermining which is continually going on. 
Locally the Redbank alternates with the Navesink due 
to slipping. At one place the layers can be traced across 
and a drop of fifty feet is noted. 
Fossils from the Navesink. 
Owing to atmospheric agencies which cause the higher 
parts to disintegrate and slide down over the more basal 
portions, it becomes necessary that the fossils of each bed 
be carefully collected and studied so as to separate them, for 
they have been generally intermixed. I have found fossils 
from a bed at the top of a bluff scattered all the way from 
the top to the bottom. Both Clark and Whitfield state that 
the fossils have been collected and labelled in such a way 
that it is impossible to tell in many instances to what beds 
they properly belong. 
The fossils in the list which follows are from the Nave- 
sink, and one of the objects of this paper is the study of 
this particular bed, ascribing to it the fossils which belong 
to it, in order to help differentiate the fossils and assign 
them to the beds to which they properly belong. 
In this list the fossils are indicated as follows : very 
common ; common ; rare, and very rare : U= given by 
Whitfield from upper marl ; M= given b}' Whitfield from 
middle marl. 
Gastropods 
m 
<G 
m 
Navesink 
o 
fc 3 
6 
£ 
o 
u £ 
^ 
ctf 
O 
U 
O 
a 
M 
U 
TJ 
Bed 3 
X 
X 
X 
X 
X 
X 
" 1 and 3 
x 
U 
" 3 
X 
Natica abyssina (Morton) 
Voluntoderma abbotti (Gabb) . . . 
Turbinopsis elevata (?) (Whitf.) 
Odontofusus medius (Whitf.) . . . 
Rostellaria compacta (Whitf.) . . 
Bulla conica (Wbitf.) 
Xenophora lapiferens (Whitf.) . . 
Lunatia halli (Gabb) 
Calyptraphorus velatus (Conrad) 
