MOSASATTRXJS. 35 



after the fossils are exposed to the air, renders them very liable to crack to pieces. 

 Earely I have seen remains of Mosasau7-us, from New Jersey, of an ochre color 

 and chalky consistence. Sometimes the fossils, but especially the teeth, are 

 remarkably weU 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. WiUiam 

 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. SpUlman 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 aU 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 vertebrae of Mosasaurus 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. WetheriU, 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 cyhndrical, 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-circular, truncated above, and measures twenty lines wide and nineteen high. 

 The hypapophysis is cylindrical, directed downward and slightly backward, and 

 measures iiine 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 seventeen lines high. The cylindrical 



