X. DESCRIPTION OF A NEW SPECIES OF BAENA (B. 



HATCHERI) FROM THE LARAMIE BEDS 



OF WYOMING. 



By O. p. Hay. 



Mr. J. B. Hatcher, Curator of the Department of Vertebrate Palaeon- 

 tology of the Carnegie Museum, has kindly placed in my hands, for ex- 

 amination and description, a specimen of the shell of a turtle which 

 he collected in Wyoming in the year 1900. This shell was found in a 

 sandstone belonging to the Laramie formation, in Converse County. 

 An examination shows at once that it belongs to the genus Baena, and 

 that it is an undescribed species. The specimen is a fine one, both 

 carapace and plastron being preserved, only a small portion of the 

 left side of the rear of the carapace being absent. The shell has 

 suffered some distortion, but not enough to interfere with a determi- 

 nation of the original form and of the elements entering into the 

 structure. Finally, the sjjecimen has been beautifully prepared by Mr. 

 A. S. Coggeshall at the Carnegie Museum. 



The genus Baena has been known hitherto only from the Wasatch 

 and Bridger beds of the Eocene, principally from the latter. This 

 discovery made by Mr. Hatcher carries the genus back to the L^pper 

 Cretaceous, a matter of great interest. 



Since the most distinctive characters of the species are found in the 

 plastron, a plate is presented showing this portion of the shell. It is 

 hoped that an opportunity will hereafter be found for publishing a 

 more complete description and for making com])arisons with other 

 species of the genus. 



The total length of the carapace has been 368 mm. ; the greatest 

 breadth, 280 mm. ; the height, from the bottom of the plastron, 

 about 145 mm. From the ends of the axis of greatest width, some- 

 what behind the inguinal notches, the carapace rounds rather rapidly 

 to the median excavation behind. 'I'he front of the carapace is rather 

 pointed. The hinder border is somewhat deeply scalloped, as in the 

 other species of the genus. 



The sutures between the various bones are fine, but most of them 

 can be traced without much difficulty. The neurals are in general 



325 



