128 REFERENCES TO THE PLATES. 



PLATE VIII. 



Figs. 1, 2. Iluracrus of 3Tosasau7-us, one-half the diameter of nature, from ucar Columbus, 

 Mississippi, belonging to the collection of Dr. Wm. Spillmau. 



Fig. 1. Posterior view. 



Fig. 2. Anterior view, a, Head of the bone; b, gi-eater tuberosity; c, lesser tuberosity ; d, strong 

 impression of muscular attachment. Length of the original specimen about ten iuches. 



Figs. 3, 4, 5. Proximal extremity of a huge bone, supposed to be of a humerus of the Moaasaurus, 

 a little less than one-third the diameter of nature. The original measures eleven inches in length 

 from the summit of the greater tuberosity to the broken end of the shaft. From the Green-sand of 

 Burlington County, Nev\r Jersey. 



Fig. 3. Posterior view. 



Fig. 4. Anterior view. 



Fig. 5. Outer or posterior border view, a, The head of the bone ; b, greater tuberosity ; c, losser 

 tuberosity ; d, impression of muscular attachment. 



Fig. C. An isolated bone, probably a radius of a small species of llosaaaurus, or of a young animal, 

 half the size of nature. Belonging to Prof James Hall, and obtained by Messrs. Meek and ilayden, 

 frctn a Cretaceous deposit of Nebraska. Length of the original specimen about two iuches and 

 three-quarters. 



Fig. 1. Supposed radius of Mosasaurus, one-half the diameter of nature, belonging to the same 

 skeleton and collection as the. humerus above indicated, from Columbus, Mississippi. Length of the 

 specimen tvco inches. 



Fig. 8. Supposed carpal bone of Mosasaurus, the size of nature. From formation, No. 4, on the 

 Big Cheyenne River; an isolated specimen, discovered by Dr. F. V. Haydeii. 



Fig. 9. Reptile bone, undetermined, one-half the size of nature. The specimen belongs to Prof. 

 James Hall, and was found by Messrs. Meek and Hayden, five miles below Dauriou's Hill Nebraska, 

 among loose fragments at the base of a Cretaceous bluff. 



Fig. 10. Reptile bone, undetermined, half the size of nature, found in company with that of 

 Fig. 8. Length one inch and three-quarters. 



Fig. 11. Basi-sphenoid bone of Mosasaurus, one-third the diameter of nature, from Holmdale, 

 Monmouth County, New Jersey, belonging to the collection of Prof. George H. Cook. Length of 

 original eight inches, breadth at the posterior diverging processes sis inches, a, Anterior ; b, pos- 

 terior processes articulating with the basi-occipital bone. 



Fig. 12. Dermal plate of a Gavial, from Burlington County, New Jersey, belonging to the collec- 

 tion of the Burlington Lyceum. One-half the natural size. 



Fig. 13. Supposed pubic bone of Madrosaurus FoUlkii, oue-fourth the diameter of the original 

 specimen. 



PLATE IX 



All the figures are of the natural size. 



Fig. 1-11. Mosasaurus. 



Pig. 1. Inner view of an alveolar fragment, apparently from the upper jaw, from Burlington 

 County, New Jersey. a, A nearly entire tooth, exhibiting on the inner side of the crown the 

 subdivisional planes ; b, exserted portion of the fang, which is coossified with its alveolus and excar 

 vated into a large cavity for a successor ; c, bottom of the cavity, exposed by the loss of a thin plate 

 of bone belonging to the alveolus ; d, orifice of the cavity at the margin of the jaw postero-internally 

 to the fang of the functional tooth ; e, portion of the alveolus in front ; /, exserted portion of the fang 

 of a tooth, the crown of which is broken off; g, bottom of the fang exposed by the breaking away of a 

 thin portion of the jaw-bone ; the sides of the fang are firmly coossified with the alveolus ; h, orifice 

 of the cavity for a successional tooth ; i, thin shell of bone remaining from the fang of a tooth, and 

 closely coossified with the sides of the alveolus. 



