Williston.] Turtles. 361 



that is lost. Both extremities are expanded, apparently about 

 the same. The upper end is thicker than the lower, and has 

 slight striate markings near the border of the articular surface. 

 About twenty-five mm. from the upper extremity, near the 

 inner border, there is a roughened protuberance, the bicipital 

 tuberosity. The shaft is quite smooth and oval. 



Carpal ? 



A single bone, which from its size I take to be a carpal and 

 not a tarsal, is very thin and flat, nearly smooth, and oval in 

 shape. It measures fifty-two mm. in its greatest and thirty- 

 eight mm. in its opposite diameter, and is nowhere over five 

 mm. in thickness. It has some very inconspicuous markings 

 near the articular margin. 



Metacarpals. 



The four bones represented in pi. lxxvi, figs. 8, 8c, were lying 

 upon the end of an ulnar fragment, and almost over the radius, 

 and nearly in the position in which they are figured, the 

 two inner ones being crossed. That they belong to the manus 

 I have no doubt, and that they are metacarpals and not pha- 

 langes seems evident from the shape of their articular ends. 

 Their measurements are as follows : 



LeDgth 48 mm. 



Width of distal extremity 9 



Length 87 



Width proximally 19 



Width distally 18 



Length 55 



Width distally 20 



Length 55 



Width proximally 15 



Another finger bone, lying across the end of the radius is 

 shorter than any of the foregoing, and may be a phalanx. One 

 end is wanting, but the end which is present and the shaft are 

 stouter than any of the foregoing. The width at the end is 

 twenty-two mm., and in the narrowest place of the shaft twelve. 

 Yet another digital bone ( fig. 10 ) seems to be a phalanx, but 



