112 



MEMOIRS OF THE CARNEGIE MUSEUM 



In order to place on record the proportional variations within the species I 

 have prepared the table of comparative measurements given below: 



CoMPAR-^TivE Measurements of Vertebrals. 



Comparative Measurements of Car^^pace and Plastron. 



Greatest length of carapace. . . 

 mdth ■ " 

 " length of plastron. . . 

 " " anterior lobe. . 



width " _ " 

 " length posterior lobe 

 width 

 Width of bridge 



No. 3243. 



366 



260 



73 

 98 



105 

 146 



e, estimated. 



3. Baena inflata sp. no v. 

 Plate XIX; text-figs. 2 and 3. 



Type : C. M. No. 3406, consisting of a carapace and plastron, the former lacking 

 the posterior end back of the middle of the fourth vertebral, the latter a small 

 portion of the anterior lobe; collected by 0. A. Peterson in 1912. 



Locality : McCook Canyon, White River, Uinta County, Utah. 



Horizon: Horizon A (near top), Uinta formation. Upper Eocene. 



The type of this species is but little crushed and, except for the parts which 

 are missing, is in a beautiful state of preservation. The surface of the carapace 

 and plastron are everywhere covered with fine pustular elevations, forming a 

 shagreened surface. The pustules on the carapace are coarser than those on the 

 plastron. The surface of the carapace is also somewhat uneven, and laterad to 

 the second, third, and fourth vertebrals there are some heavy longitudinal wrink- 

 lings. These are most numerous laterally at the junction of the third and fourth 

 vertebrals. The pustular ornamentation of the carapace appears to be very 

 similar to that of Baena sirna Hay, but not so coarse. 



The greatest length of the shell is estimated to have been about 400 mm. ; its 

 greatest width at the center is 310 mm. In outline the front of the shell is evenly, 



