GILMORE: the fossil turtles of the UINTA FORMATION 115 



slightly convex transversely throughout its length, and this convexity on the bridge 

 area continues evenly to the borders of the shell, so that these borders stand 36 mm. 

 above the level of the plastron at the center. The anterior lobe has its greatest 

 width (135 mm.) at the base; and at a point half-way to the anterior end it measures 

 99 mm. The sides of the lobe converge gradually from the base to the anterior 

 end, which appears to have been rounded. The width of the bridge is 175 mm. 



The posterior lobe is tongue-shaped, shallowly, but broadly notched. Its 

 length on the midline is 97 mm., with a width at the base of 139 mm. The notch 

 has a depth of 6 mm. at the center. 



Excepting those of the anterior lobe all of the sulci and sutures on the plastron 

 can be clearly made out. The mesoplastrals widen rapidly on either side of the 

 midline. At the center the right scute measures 51 mm. The width of the right 

 hypoplastral at the center is 104 mm.; of the left hypoplastral 91 mm. The xiphi- 

 plastrals are 62 mm. wide on the midline. The pectorals meet on the midline for 

 a distance of 75 mm.; the abdominals for 49 mm.; the femorals for 80 mm.; the 

 anals for 47 mm. 



On the right side are three inframarginal scutes, the form of which is well 

 shown in Fig. 3. 



A second specimen, C. M. No. 3442, belonging apparently to this species, was 

 collected by Earl Douglass in 1915 from the lower part of Horizon B of the Uinta 

 formation, at Wagon-hound Bend on White River, Uinta County, Utah. This 

 turtle consists of a carapace and plastron, both of which have small portions 

 missing from their posterior ends. In size, general contour, and the dimensions 

 of the dermal scutes, the specimen closely resembles the type. The inflation of the 

 sides of the carapace, which forms such a conspicuous feature in the type, is almost 

 entirely wanting in this individual. Its absence may be attributed in part, at least, 

 to crushing, for both sides in this respect have somewhat suffered. There are also 

 no supernumerary costal scutes at either side of the first vertebral, and in their 

 absence the first vertebral is tetragonal, whereas in the type it is hexagonal with 

 the narrow end in front. This specimen shows small triangular first marginals 

 on either side of the nuchal, and in the drawing of the type (Fig. 2), this region, 

 which is missing, has been restored after this specimen. It also gives the complete 

 form of the anterior lobe (See Fig. 3), which in its general contour closely resembles 

 Baena sima Hay. 



The greater part of an anterior lobe, C. M. No. 3137, which was collected by 

 Earl Douglass in the strata of Horizon B of the Uinta formation, near Well No. 2, 

 Uinta Basin, Utah, in 1908, is regarded as belonging to Baena inflata. It is from 



