44 THE STRUCTURE AND LIFE OF BIRDS cHAP. 
wing is very different from the pterodactyl’s. To the 
support of the latter only one finger, often called the 
ulnar finger since it articulates with the postaxial side 
Fic. 17.—(1) Pterodactylus Spectabilis, from lithographic-stone, Bavaria. 
of the arm, contributes, and this one may be either No. 
4 or No.5. The settlement of the question depends 
upon the nature of the small bone which can be seen 
