>S. W. Williston — Restoration of Limnoscelis. 465 



complete and undistorted, as shown in figs. 13 and 14, they are 

 remarkably stout and long. They are directed outward, down- 

 ward, and backward, and end in a truncated extremity. They 

 lie, for the most part, below and back of the iliac process. It 

 seems certain that ribs of such structure and strength in this 

 position must have served some functional use in the support 

 of muscles, doubtless for ones controlling movements of the 



Figs. 27-31. 



Fig. 27, 28, ulna and radius, dorsal sides, Y. U. 811. Fig. 29, right tibia, 

 ventral side, Y. U. 811. Fig. 30, left ischium, outer side, Y. U. 809. Fig. 

 31, right humerus, distal end, C. U. 650. 



leg. Back of these greatly enlarged and long ribs, the suturally 

 united caudal ribs progressively decrease in length and size, dis- 

 appearing on the eleventh or twelfth. 



In my first paper I stated that the first chevron was attached 

 to the third caudal vertebra ; this statement is true if the second 

 vertebra with sacral rib attachments is considered a sacral, not 

 otherwise. The first chevron preserved in specimen 809 is 



