279 



Two limb-bones, represented in Figs 13, 14, Plate XXXVI, pertaining 

 to the same collection, are supposed also to belong to the same animal as the 

 above. I feel unable to determine their character. The broader one I sup- 

 pose to be an ulna or a fibula. It resembles in its shape and construction 

 the corresponding bone of the New Mexico mosasauroid, represented in Fig. 

 10, Plate XXXV, but is much smaller. 



Its measurements are as follows: 



Inches. Lines. 



Length at the upper extremity < 4 3 



Breadth of upper extremity 2 ' 9 



Thickness of upper extremity , . . 10 



Breadth of lower extremity 3 4 



Thickness of lower extremity 7 



Width of shaft at middle 2 



Thickness of shaft at middle , . . 11 



The smaller bone of Fig. 14 is probably a radius or a tibia. 

 Its measurements are as follows : 



Inches. Lines. 



Length , 3 7 



Breadth of upper extremity •. . , 1 4.] 



Thickness of upper extremity 9 



Breadth of lower extremity 1 10 



Thickness of lower extremity 9 



Width of shaft at middle 9 



Thickness of shaft at middle 7 



MOSASAURUS (?) 



The cabinet of Swarthmore College, in the vicinity of Philadelphia, con- 

 tains a number of fossils from the Cretaceous formation of Nebraska, pre- 

 sented by Mr. George S. Truman. They were collected by him from the 

 hills on the Missouri River, near the Santee Agency, in L'Eau qui Court 

 County. They consist of bones and teeth of fishes and reptiles, among 

 which are a number pertaining to the Polycotylus latipinnis of Professor 

 Cope, originally described from remains found in Kansas. 



An anterior caudal vertebra of a Mosasaurus, in Mr. Truman's collection, 

 is represented in Fig. 15, Plate XXXVI. The vertebra has the form usually 

 assigned to the genus. It retains the neural arch, but has lost its spine. 

 From the lower part of the body project the roots of strong transverse pro- 

 cesses. Beneath the body there is a strong pair of eminences projecting just 



