MOSASAURUS. 35 
after the fossils are exposed to the air, renders them very liable to crack to pieces. 
Rarely I have seen remains of Mosasawrus, from New Jersey, of an ochre color 
and chalky consistence. Sometimes the fossils, but especially the teeth, are 
remarkably well preserved, and of very firm texture. Usually the enamel of the 
teeth is jet black and shining ; occasionally gray, with brownish stains. 
Besides the New Jersey specimens, I have seen a few others from the Cretaceous 
formations of the Upper Missouri, collected by Dr. F. V. Hayden, several from a 
deposit, of the same age, near Columbus, Mississippi, obtained by Dr. William 
Spillman, and one from near Marion, Alabama. 
I have been unable to satisfy myself whether the specimens from the Upper 
Missouri, described by Dr. Goldfuss, and those submitted to my examination by Dr. 
Hayden, belong to the same species as the remains of the New Jersey Mosasaurus. 
The specimens sent to me for inspection by Dr. Spillman consist of a basi-occipital 
bone, a tympanic bone, the greater portion of a pterygoid bone with teeth, a hu- 
merus, several vertebrae, and a few fragments of others. ‘These were imbedded in 
a greenish sandstone, and apparently all belonged to the same individual, which I 
think was a different species, if not another genus, from the New Jersey Mosasaurus. 
The museum of the Academy of Natural Sciences of Philadelphia contains thirty- 
two specimens of vertebra of Mosasawrus from the Green-sand of New Jersey. They 
are chiefly from Burlington and Monmouth Counties, and were presented to the 
Academy by Mr. J. P. Wetherill, Dr. S. G. Morton, Dr. Charles T. Budd, Mr. T. 
Conrad, Dr. J. H. Slack, and Mr. L. T. Germain. The specimens belonged to a 
dozen or more individuals of different ages and sizes. All are much mutilated ; 
one only retaining the vertebral arch. They consist of the following :— 
1. A large cervical or anterior dorsal vertebra, represented in Fig. 1, Plate VII, 
from Monmouth County, N. J. The body measures three inches and a half from 
the bottom of the anterior concavity to the summit of the posterior convexity. The 
latter is sub-rotund, nearly as wide as high, measuring about two inches and two 
lines in diameter. The breadth of the specimen is six inches between the ends of 
the transverse processes, which are robust, conoidal, and project from the fore part 
of the body and abutment of the vertebral arch, obliquely backward, outward, and 
slightly downward. The spinal canal is obcordate, and about fourteen lines high 
and wide. ‘The hypapophysis springs from a broad carina-like base, and is directed 
obliquely downward and backward. It is cylindrical, sixteen lines in transverse 
diameter, and truncated at the extremity, which is depressed at the centre into a 
conical pit. 
2. A mutilated body of a cervical or anterior dorsal vertebra, from Burlington 
County, N. J. The body is two inches and a half long. Its posterior convexity is 
sub-cireular, truncated above, and measures twenty lines wide and nineteen high. 
The hypapophysis is cylindrical, directed downward and slightly backward, and 
measures nine lines in transverse diameter. 
3. Two bodies of cervical or anterior dorsal vertebrae, one of which is repre- 
sented in Figs. 2, 3, Plate VII. The body is two inches and five lines long, but 
broader in relation with its height than in the preceding. The posterior convexity 
is reniform in outline, two inches wide and seventcen lines high. ‘The cylindrical 
