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I. DESCRIPTION OF A NEW SPECIES OF TORTOISE FROM 

 THE JURASSIC OF UTAH. 



By Charles W. Gilmore. 



(Plates I-II.) 



By the kindness of Dr. W. J. Holland, Director of the Carnegie 

 Museum, I am permitted to study and describe the large series of 

 fossil chelonian remains, which that museum has accumulated during 

 the years since 1906, before which time the collections in Pittsburgh 

 were subjected to study by Dr. O. P. Hay. It is proposed to treat 

 these collections in a series of articles, each to be devoted to the turtles 

 of a particular formation. The turtles from the Morrison beds are 

 the basis of the present communication. Being the most ancient of 

 any found in North America, they are of peculiar interest. 



There are three specimens in the collection, all from the extensive 

 quarry near Jensen, Uinta County, Utah, from which the Carnegie 

 Museum has obtained a wonderful collection of the remains of 

 sauropodous dinosaurs. One of these specimens. Cat. No. 341 1, 

 pertains to the well-known genus and species Glyptops plicahdus 

 (Cope), and is only of interest as greatly extending the known geo- 

 graphical range of this species. The remaining specimens I regard 

 as representing a new species of Glyptops to be described in the follow- 

 ing pages. The better preserved specimen, Cat. No. 3380, although 

 differing in several features from the type, is for the present at least 

 referred to the same species. 



Glyptops utahensis sp. nov. 



Type: Cat. No. 3412, complete carapace and plastron; Paratype: 

 Cat. No. 3380; both specimens collected by Earl Douglass, 1913, 

 at Carnegie Dinosaur Quarry, near Jensen, Uinta County, Utah. 



Horizon: Morrison, Upper Jurassic. 



The carapace of the type, when compared with Glyptops plicatulus 

 (Cope), is relatively long and narrow, with a depressed shell, having 

 its greatest depth of 63 mm. at the center. Transversely the carapace 

 is evenly convex, but antero-posteriorly the front portion is but little 

 below the level of the back, whereas the posterior portion descends 



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