TESTUDINID^E. 



429 



front, convex behind, with two distinct surfaces, forming a ginglymoid joint. The seventh has 

 both ends concave. The eighth has a ginglymoid concavity in front, and a rounded head 

 behind. The dorsal vertebrae have all been destroyed. 



The pelvis of T. osborniana appears to have been narrower than that of T. impensa, the 

 width of the former, taken across the pubes from the lower border of one acetabulum to that 

 of the other, being 172 mm.; in the latter species, 195 mm. 



Besides the large individual described above, Dr. Loomis discovered several others of 

 smaller sizes. One of these, No. 6080, has a carapace 400 mm. long and 335 mm. wide. 

 Another has the carapace 266 mm. long and 218 mm. wide. The shell is complete and only 

 slightly distorted. It is numbered 5871 and is one of five which were piled closely together. 

 Two of these were too much injured to be worth saving. These shells appear to have 

 drifted to their place of burial, for there were no remains of other bones of the skeleton with 



;6i. 



- 



562. 



Fics. 561 and 562. Testudo osborniana. Carapace and plastron of young individual 



Xj. No. 5871 A. M. N. 11. 



561. Carapace. 



562. Plastron. 



them. No. 5871 furnishes figs. 1, 2, of plate 75; and text-figs. 561 and 562. In form the 

 younger individuals differ from the adults in being more rounded in front, the angles at the 

 third peripherals not having vet been developt. The peripherals of the bridge region are not 

 so high relatively as in the adults. 



The plastron of No. 5871 (text-fig. 562) has a total length of 253 mm. The anterior lobe 

 is 67 mm. long and 142 mm. wide at the base. The lip is 62 mm. wide at the base and is 

 slightly notcht in front. The upper surface is like that of the larger specimens. The bridges 

 are 125 mm. wide. The posterior lobe of the plastron is 60 mm. long and 130 mm. wide at the 

 base. It is broadly notcht behind. 



A still smaller individual found by Dr. Loomis is numbered 5873. It furnisht a shell only 

 slightly damaged and not at all crusht, so that in it we have the form of the young. The shell 

 is high and tumid. The peripherals above the bridge and the distal halves of the costals are 

 ornamented with longitudinal grooves and ridges, which mark the growth of the horny scutes. 

 This, like the other younger individuals, has a low boss on the first neural bone. 



