96 



COMPARATIVE ANATOMY. 



Dinosaurians the latter (Fig. 81, *) is more strongly developed, 

 and plainly leads towards the form of pelvis seen in Birds. 



FIG. 81. PELVIS OF Iguanodon bernisaartensis. (After Dollo.) 



*, preacetabular, and Jl, postacetabular process of the ilium ; a, acetabulum (per- 

 forated) ; P, pars acetabularis (pectineal process of pubis) ; P 1 , pubis ; Jt t 

 ischium. 



FIG. 82. PELVIS OF Aptcryx australi*. (Lateral view. ) (After Marsh.) 

 ?7, ilium ; is, ischium ; p, pectineal process of pubis ; p 1 , pubis ; a, acetabulum. 



In Birds (Fig. 82), both pro- and postacetabular portions of 

 the ilium are largely developed, but vary in their relative propor- 

 tions (comp. p. 44). In Crocodiles the pubis is to a great extent 



