LIFE AND KINSHIP OE DINOSAURS. 



603 



exceptions are chiefly seen in the wingless forms, Apteryx, e. g., and the Cassowary, in 

 which latter bird the expanded acetabular and of the pubis projects forward, at 5, beyond 

 the joint, a, in a pointed form, about six lines in length. The proximal end of the pubis 



Fig. 12. 



EiG. 13. 



Fig. 14. 



Dinosanr. 



Crocodile. 

 Pelvic ebaracters. 



Dinornis. 



enters into the formation of the acetabulum in all birds. The distal end terminates, 

 in most birds, freely ; in some it is anchylosed to the ischium ; in the Ostrich it joins its 

 fellow to form a symphysis pubis :* in all it is directed backward and downward. 



In the Monotremes the pubis (fig. 15, Ornithorhi/nchus) sends off from its fore part, 

 about one third of its length from the acetabular end, a, a low and broad process, «•, 

 giving attachment to the outer part of the base of the marsupial bone. It joins its 

 fellow at the expanded distal end, s, and joins at/, the corresponding end of the ischium, 



* For other modifications, which, however, give no help in the present inquiry, see my ' Anatomy of 

 Vertebrates,' vol. ii, pp. 35, 36. 



