184 



CHAMELEO. 



Chameleo peistinus. 



A small fragment of a lower jaw with teeth, discovered by Dr. Carter in 

 the Bridger Tertiary formation, is represented in Figs. 38, 39, Plate XXVII, 

 magnified three diameters. In every respect it agrees with the correspond- 

 ing part of tlie jaw of tlie living chameleons, but^ indicates a much larger 

 species. In a space of 5 lines the alveolar border is occupied by eight teeth 

 successively increasing in size from Ijefore backward. 



The teeth are laterally compressed conical, with the borders in front and 

 behind somewhat extended and acute, and at the base produced into a minute 

 denticle. Externally the bases of the teeth are separated by perpendicular 

 furrows descending on the face of the jaw to the position of a finely perforate 

 horizontal line. Beneath the bases of the teeth internally there is a wider 

 and more conspicuous horizontal and perforated groove. Below this, toward 

 the rounded base of the jaw, the usual Meckelian groove is situated. The 

 outer face of the jaw exhibits two vasculo-neural foramina. The depth of 

 the lower jaw from the point of the last tooth of the specimen is 2 J lines. 



FISHES. 



The remains of fishes in the Bridger beds are not so abundant as one might 

 have supposed from the nature of their composition and the conditions of their 

 origin. Nevertheless, it is probable that fishes were abundant in genera, 

 species, and individuals in the great Uintah Lake and its tributaries, whose de- 

 posits form the Bridger beds. The same circumstances which removed the 

 less coherent parts of the skeleton from the interior of the many turtles, and 

 likewise scattered the bones of these and of the multitude of other reptiles 

 and of mammals, no doubt served to destroy the more delicate strncture of 

 the fishes and to distribute their hard parts through the mud. It is probable 

 that future explorations may lead to the discovery of some strata of the Bridger 

 beds in which well-preserved forms of fishes may exist like those found in the 

 shales of the deeper beds of Green River. 



The remains of fishes from the Bridger beds, which, with few exceptions, 

 were found by Dr. Carter and submitted to my examination, consist mainly of 

 smoothly enameled ganoid scales, a few isolated specimens of vertebral centra, 

 portions of spinous raj^s, and fragments of jaws with tcetli. My means of 

 comparison of these specimens with the skeletons of recent fishes are ex- 



