182 



tions with the other bones, that it leads to the suspicion that it may not belong 

 to the same skeleton. 



No scales were ibund in association with the bones in the same mass of 

 rock. 



The name Saniwa, according to Professor Hayden, is nsed by one of the 

 Indian tribes of the Upper Missonri for a rock-lizard-. 



Saniva major. 



Several fragments, discovered by Dr. Carter near the Lodge-Pole Trail, 

 crossin'g Dry Creek, would appear to indicate a larger species of Saniva. The 

 specimens are of a greenish hue and somewhat smooth or water-worn, and 

 were derived from a green sandstone stratum. 



One of the fossils consists of the distal extremity of a humerus, repre- 

 sented in Fig. 14, Plate XV. It resembles in general aspect the correspond- 

 ing portion of the humerus of the monitor, but the shaft is proportionately 

 more robust, and not so much narrowed toward the middle. It is occupied 

 by a large medullary cavity with compact walls, as in the humerus of a bird. 

 The internal epicondyle appears less prominent than in the monitor, in con- 

 sequence of the less degree of contraction of the shaft. The external epicon- 

 dyle does not reach upward to more than half the relative extent it does in 

 the monitor, and it is not perforated. The ulnar eminence is prominent in 

 front, but projects below to a less degree than the radial capitellum. 



The breadth of the bone at the epicondyles is f of an inch. The greater 

 diameter or breadth of the shaft at the broken end is 3| lines ; the short 

 diameter is 2^ lines. 



Another of the fossils consists of a pair of dorsal vertebras, represented in 

 Figs. 36, 37, Plate XXVII. They agree in all respects with the two vertebrae 

 referred to the former species, except that they are considerably larger. 



The bodies of the vertebrae inferiorly measure 7| lines in length and lOi 

 lines in width between the diapophyses. The ball measures 5 lines in In-eadth 

 and 3 hnes in height. The neural arch laterally at the zygapophyses is 10 

 lines in length 



GLYPTOSAURUS. 



Professor Marsh has described, in the American Journal of Science and 

 Arts for 1871, another genus of extinct lizards, under the above name, from 

 remains obtained in the liridger Tertiary. He observes that "the head was 



