williston: new cretaceous turtle. 15 



Length of second sacral vertebra 21 mm. 



Length of first sacral vertebra 24 



Width through the articular surfaces for the trans- 

 verse processes 31 



Width of transverse process at base 17 



Width of transverse process distally 1 1 



Length of transverse process 45 



Length of first presacral vertebra 29 



Width of centrum anteriorly 22 



Width through rib processes 25 



Length of second presacral vertebra 40 



Width of centrum anteriorly 24 



Width through rib processes 29 



Distance between inferior margin of same vertebra 



and the top of the carapace 40 " 



Eight marginal bones are present, including the pygal. Whether 

 they are all from the samfe side or not I do not know; but all are 

 different. Lying in position, with the anterior projection touching 

 nearly the posterior end of the united carapace is the pygal which is 

 figured, the surface which is represented being the upper one, and 

 the attached marginal belonging to the right side. Lying beneath it, 

 near the margin, were two small caudals, one of which is shown in 

 the figure. The pygal and adjacent marginal are very flat bones, 

 very thin on the outer margin, somewhat roughened on the anterior 

 part. A fragment of the attached left marginal is present, but is not 

 shown in the figure. The sutural union, here as elsewhere is firm. 



Length of pygal 97 mm. 



Width at the ends 42 " 



Width across the middle 61 ' " 



Thickness near anterior border 6 " 



Length of adjacent marginal 64 " 



Width •. 45 " 



Thickness 5 " 



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£ 



Pygil and contij;iious light inu^mil of Dcvu^i/oc'ieli/s LwdU. two-thirds natural size. 



Lying in contact with a hyo- or hypoplastron is one complete 

 marginal, and portions of two others partly detached. The bones 



