THE PECTORAL AND PELVIC GIRDLES 



139 



adult life, but it is free in the crocodiles, and more or less suturally 

 loose in the early pterosaurs, dinosaurs (Fig. 113), phytosaurs (Fig. 

 in), and rhynchocephalians. 



The scapula of the plesiosaurs (Figs. 102, no) is peculiar in the 

 development of a strong proscapular process projecting downward, 

 forward, and inward, and often meeting its mate in a median 

 symphysis, a character unique among vertebrates. The blade is 



