110 BOTHREMYS. 
cially interesting from the fact that it presents on its upper surface an oblong 
elliptical suture for the pelvis. Such an articulation would, perhaps, indicate a 
nearer affinity of this extinct Turtle to the existing Sternotherus, than to Platemys, 
with which I have associated it. 
I have also seen small fragments of two other xiphisternals, with the pelvic 
sutures, together with a fragment of a costal plate, apparently of a much younger 
individual, of the same species as the foregoing, obtained by Dr. Wm. B. Atkinson, 
from the Green-sand of Mullica Hill, Gloucester County, New Jersey. 
BOTHREMYS. 
Bothremys Cookii. 
In June, 1862, Frof. Cook sent to me, for examination, the skull of a Turtle, 
from the Green-sand near Barnsboro, Gloucester County, New Jersey, which, inde- 
pendent of its special or generic peculiarities, is of interest from the circumstance 
that it is the first Chelonian skull brought to my notice from the Green-sand forma- 
tions of the United States. 
The specimen, represented in Figs. 4-8, Plate XVIII, consists of the greater 
portion of a skull together with the lower jaw. Of the former the occipital region, 
the auditory passages, the zygomatic arches, and some other minor parts are lost; 
of the latter the condyloid portions are destroyed. 
Of all recent Turtles with which I am acquainted the fossil skull, in general 
physiognomy and structure, resembles most that of the great Turtle of the Amazon, 
Podocnemys expansa. From this, and all others, however, it differs in several 
striking peculiarities. 
The fossil skull is remarkable for the great proportionate breadth of the face, 
due to the accommodation of a large conical pit formed by each maxillary bone, as 
seen in Fig. 7, a. 
The top of the skull (Figs. 4, 6) is nearly flat, inclining forward in a slight 
degree, and becoming slightly more convex approaching the orbits and the interval 
between them. ‘The face in the latter position is broad, slightly convex, and slopes 
regularly to the anterior nasal orifice. Below and behind the orbits the face 1: of 
great proportionate depth, and slopes obliquely downward and outward with a 
moderate degree of convexity. Transversely the lower boundary of the face forms 
a semicircle, broken only by a moderate pointed protrusion of the premaxillaries. 
The orbits are comparatively small and circular, and look obliquely upward, 
forward, and outward. 
The anterior nasal orifice is of great proportionate breadth, its transverse diameter 
being twice as great a$ the vertical. It is in the form of a double annulus or a 
prostrate figure of 8. 
The temporal fossee are large, but whether they have been covered by a bony 
vault, as in the great Turtle of the Amazon and the marine Turtles, cannot be 
ascertained in consequence of the imperfection of the fossil. 
The upper jaw is defined below, in the usual manner in ‘Turtles, by an acute ridge 
for accommodating the corneous dental armature of the jaw. 
