4 PROCEEDINGS OF THE ACADEMY OF 



the lower border of the body, as is indicated to be the case in the Tilgate 

 specimens. The posterior articular surface of the body is moderately de- 

 pressed, but its lower fourth curves forward, producing a thick, convex ledge 

 for the accommodation of a chevron. The breadth of the articular surface is 

 scarcely four inches, and its depth is about the same measurement. 



The species represented by the fossil maybe named Poiciloplecron valens. 

 Should the division of the medullary cavity of the vertebral body into smaller 

 recesses by trabeculas be significant of other characters indicating the Colo- 

 rado saurian to be distinct from Poicilopleuron, it might be named Antro- 

 demus. 



2. A collection of fossils from the cretaceous formation of Pickens Co., 

 Alabama, received from Dr. J. C. Nott, formerly of Mobile, indicates a mosa- 

 sauroid reptile apparently of the genus Clidastes, of Prof. Cope. The speci- 

 mens consist of an anterior portion of one ramus of the lower jaw, a portion 

 of the upper jaw, an axis and several dorsal vertebrae. The species was of 

 intermediate size to C. iguanavus of the cretaceous of New Jersey and C. 

 propython of Uniontown, Alabama. It may be named Clidastes intermedins. 

 The jaw fragments indicate more robust proportions than in C. propython. 

 The fragment of the lower jaw is 5 inches long and contains a series of 

 nine teeth ; the depth of the symphysis is one inch ; the depth below the 

 seventh tooth almost an inch and a quarter. 



The body of a dorsal vertebrae is almost an inch and a half long ; its ar- 

 ticular cup is a little over an inch wide and about three-fourths of an inch 

 vertically. The neural arch retains the zygosphene and zygantrum, indicat- 

 ing the iguanian character of the extinct reptile. 



Since communicating the above I have received for examination some 

 remains apparently of the same species, from the cretaceous formation of 

 Kansas. Among them are two nearly entire dentary bones, the length of 

 which is about eleven inches. They contain the bases of the teeth, indicating 

 the full series to be twelve. The more slender jaws of C. propython, with 

 the dentary bones about the same length, contain a series of about eighteen 

 teeth. 



3. The caudal vertebra represented in figures 15, 16, plate II, of the " Cre- 

 taceous Reptiles of the United States," indicates a reptile apparently of the 

 genus Leiodon or Macrosaurus. The constitution of the vertebra is the same 

 as in the caudals of the known species of this genus. It probably belongs to 

 the species described by Prof. Cope under the name of M. proriyer. 



4. The fine specimen of a fossil turtle exhibited to the Academy was loaned 

 by Mr. 0. C. Smith, of Amherst, Mass., through Prof. Hayden, for my exami- 

 nation. It was obtained, as the latter informs us, from the Bridger Group of 

 tertiary rocks, probably of miocene age, in the vicinity of Fort Bridger, 

 Wyoming. It appears to represent an extinct genus, approaching in char- 

 acter the existing Dermatemys of Central America, and was nearly of the size 

 and shape of Dermatemys Mawii, Gray, of Vera Cruz and Tabasco, C. A. 



The carapace in its general form and construction especially resembles that 

 of the latter. It has the same elongated vertebral plates and scutes. The 

 sternum is intermediate in its proportions and shape with those of Dermatemys 

 and Staarotypus. The interspaces of the carapace and sternum are very much 

 larger than in the former, but proportionately less than in the latter. The 

 pedicles of the sternum are not so deep as in Dermatemys, but are much wider. 

 The back part of the sternum, intermediate in its proportious with what it is 

 in Dermatemys and Staurotypus, ends in a posterior narrowly rounded ex- 

 tremity, not acute as in the latter, nor emarginate as in the former. Derma- 

 temys has two large scutes intervening between the unusually large inguinal 

 and axillary scutes. In Staurotypus the axillary and inguinal scutes meet 

 across the sternal pedicles. In our fossil a single large hexagonal scute in- 

 tervenes to the axillary and inguinal scutes. The latter are much larger 



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