Williston.] Turtles. 363 



Pubis. 



The pubis is much thickened at the acetabular end, expanded 

 and thin at the symphysial end. The side exposed, the inner, 

 shows two facets separated by a distinct angle. The ischial 

 border is deeply concave, and for the most part thin. The bone 

 is narrowest midway, and the whole lower part is evidently 

 thin. Unfortunately, the anterior inferior portion has been lost. 

 The surface exposed is nearly plane throughout, though it prob- 

 ably had some curvature. There are no indications on either 

 pubis or ischium of union with the plastron. 



Width of acetabular extremity 37 mm. 



Length of ischial facet 25 



Length of bone as preserved 108 



Femur. 



The only bone of the hind extremity preserved is an incom- 

 plete femur, which lies directed backwards, with the great 

 trochanter immediately below the sacral end of the ilium. Its 

 great trochanter is flattened, high, and broad, with distinct 

 rugosities on the outer side. The head is a small, oval articular 

 surface surmounting a rather thin, small plate placed nearly at 

 right angle to the plane of the trochanter and at one side. Just 

 back or below the head is a distinct depression or "digital" 

 fossa, with a muscular rugosity near it. On the outer, or dorsal 

 convex surface, near the narrowest part of the shaft, there are 

 two roughened surfaces, one on the border opposite to that of 

 the head forming a rounded tubercle about half an inch in diam- 

 eter. The lower part of the bone is expanded and quite thin. 



Width of trochanter 32 mm. 



Height of trochanter above the head 25 



Height of head above plane of trochanter 20 



Length of articular surface of head 10 



Width 7 



Width of shaft 25 



Thickness of shaft 12 



Width near lower extremity as figured 40 



Thickness 6 



