36 MOSASAURUS. 
hypapophysis, 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 outline, thirty-one lines wide 
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 hypapophysis, 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 vertebra, 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 Figs. 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, 18, 14, Plate VII. 
11. Four large caudal vertebra 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- 
