MOSASAURUS. 69 
the other from near Woodbury, Gloucester County, New Jersey, presented to the 
Academy by Dr. J. L. Burtt. The former is represented in Fig. 12, Plate X; the 
latter in Fig. 13, of the same Plate. 
They resemble the crown of the tooth last described, but are in a No. 27. 
better condition of preservation. ‘They are divided in the usual 
manner into two surfaces, of which the inner is rather more convex 
than the outer, and both are distinctly subdivided into planes. The 
New Jersey specimen, of which the outline, No. 27, represents a 
transverse section, presents four planes on its outer side and seven 
on its inner side; and it measures eighteen lines in length, nine lines 
and three-quarters antero-posteriorly at base, and seven lines trans- No. 28. 
versely. The Delaware specimen, of which the outline, No. 28, is a 
section, exhibits seven planes externally and internally, amd measures seventeen lines 
long, nine lines and a quarter antero-posteriorly at base, and six lines and a half 
transversely. 
28. A tooth, from Mount Holly, Burlington County, New Jersey, presented to 
the Academy of Natural Sciences by Dr. 8. G. Morton. The crown has its apex 
broken off, and the ridges dividing the former are considerably worn, When 
perfect it has been about an inch and a half long; with the base ten lines and a 
half antero-posteriorly, and eight lines transversely. The surfaces are devoid of 
subdivisional planes, or exhibit only the faintest traces of several towards the back 
border of the crown. ‘The inner surface more convex than the outer, has the curve 
of its base eighteen lines in width, while the outer one is thirteen in width. 
The fang is entire, and appears not to have been coossified with its alveolus. 
The exserted portion forms a curved shoulder measuring externally only five lines 
in length, while at the border it is sixteen lines in antero-posterior diameter, and 
thirteen lines in transverse diameter. ‘The intra-alveolar portion of the fang is an 
inch and a half long, straight, somewhat compressed, and tapering below. On its 
inner side posteriorly is a small excavation for a successional tooth. 
29. A fragment of a jaw, with portions of three alveoli, of which one contains 
the fang of a tooth deeply excavated and containing a successor. The specimen 
is from Marlboro, Monmouth County, New Jersey, and was loaned to me, from the 
collection of Rutger’s College, by Prof. Cook. 
The successional tooth, of which an inner view is represented No. 29. 
in Fig. 11, Plate XI, is a crown with a large interior pulp cavity 
and thin walls. From the apex to the broken edge of the base 
it measures about twenty-two lines in length. In transverse 
section it is irregularly elliptical, as represented in the outlines, 
No. 29; its inner curvature being more convex and longer than 
the outer. The anterior and posterior acute ridges are minutely denticulated, and 
the surfaces they separate are totally devoid of subdivisional planes. 
30. Two small teeth, from Freehold, Monmouth County, New Jersey, belonging 
to the collection of Dr. C. Thompson, and loaned to me through Prof. Cook. They 
are represented in Figs. 14, 15, Plate X, and appear to have belonged to the same 
individual. 
