36 MOSASAURTTS. 



liypapophysis, ten lines in diameter, projects from the middle of the body directly 

 downward. 



■4. The body of a dorsal vertebra, not possessing a hypapophysis. Length three 

 inches and a quarter ; posterior convexity reniform in outhne, thirty-one lines v^ide 

 and twenty-one high. The remaining roots of the robust transverse processes spring 

 from the body at its conjunction with the vertebral arch. 



5. A series of three dorsal bodies, without hj'papophysis, and measuring two inches 

 and a half long. The roots of the transverse processes are situated at the middle 

 of the sides of the body. The posterior convexity is reniform, thirty-two lines wide 

 and twenty-three high. 



6. A dorsal body with robust, conoidal transverse processes projecting from the 

 forepart outward and backward. Length of body thirty lines ; posterior convexity 

 thirty lines wide, twenty-two high. 



7. The body of a much mutilated dorsal vertebra, with the same form as the 

 latter but larger. 



8. Two bodies of lumbar vertebrte, with the remains of long, flattened transverse 

 processes projecting outward and downward from the lower part of their sides. The 

 posterior convexity is widest at its lower third, and narrows to the emarginate 

 border of the spinal canal. Length of body in one specimen twenty-six lines, in 

 the other twenty-three ; greatest width of posterior convexity in both specimens 

 thirty-one lines, height twenty-four lines. This form of vertebra is represented by 

 Fig. 4, Plate 247, of the fourth edition of Cuvier's Ossemens Fossiles. The larger 

 of the two specimens is represented in Fig.s. 9, 10, 11, Plate VII. 



9. Five very much mutilated specimens of the same character as the preceding, 

 but larger. From two different individuals and localities. The largest specimen 

 is thirty-two lines long ; the smallest twenty-six lines. 



10. Five small vertebrae of the same form as the preceding, from several indivi- 

 duals and localities. The largest specimen is twenty-one lines long ; the smallest 

 eighteen lines. Two are represented in Figs. 12, 13, 14, Plate VII. 



11. Four large caudal vertebrae with the same form of body, and with roots of 

 transverse processes having the same form and position as in the preceding. In 

 addition, roots of chevron bones project from the posterior inferior part of the 

 bodies. The most perfect of the specimens has the length, width, and height 

 equal, being thirty-nine lines in these different directions. 



12. Two caudal bodies with lateral tubercles or mere rudiments of transverse 

 processes ; otherwise having the same form as the preceding, but smaller, their 

 length being twenty-seven lines. 



13. Three much mutilated caudals, relatively narrower than the former. The 

 largest is twenty-eight lines long ; the smallest twenty-four lines. 



14. The body of a caudal vertebra, fourteen lines long. 



Since writing the foregoing I have received, for examination, from Prof. Cook 

 the following specimens : — 



1. A dorsal vertebra, from Freehold, Monmouth County, N. J., loaned by Dr. C. 

 Thompson. The specimen corresponds in form with a rather larger one previously 

 described, and is represented in Fig. 8, Plate VII. It also bears considerable re- 



