PLATE IV 



[All three Figures on this Plate have been reduced rather more than one-fifteenth 



in size] 



Fig. 25. Inner aspect of about the distal two-thirds of the right tibio-tarsus of 

 Ilesperornis regalis Marsh. (Plaster cast of the type bone.) Compare with Figures 

 on Plate III. (No. 56 of the palaeontological collection (Bird Division) of the U. S. 

 Nat. Mus.) 



Fig. 26. Same specimen as shown in Figure 25 and viewed upon its anterior 

 aspect. < 



Fig. 27. Same specimen as shown in Figures 25 and 26 of this Plate and viewed 

 upon itf posterior aspect . 



