Page:The Osteology of the Reptiles.pdf/167

Rh, or rather of that division called the Predentata, or order Ornithischia. In the other divisions, the Theropoda (Fig. 122 ) and Sauropoda (Fig. 122 ), the pubes have the normal reptilian structure, though unusually stout and strong, meeting in the middle below in a firm symphysis, much elongated in the Theropoda. The symphysis of the ischia is less strong.



. 122, Pelves (Dinosauria): A, Ceratosaurus (Saurischia). After Marsh. One sixteenth natural size. B, Apatosaurus (Saurischia). After Marsh. One thirty-second natural size. C, Triceratops (Ornithischia). After Marsh. One twenty-fourth natural size. D, Stegosaurus (Ornithischia). After Marsh. One twentieth natural size. E, Trachodon (Ornithischia). One tenth natural size.

The pubes of the Ornithischia (Fig. 122 ) have been the subject of much dispute and speculation. Each is composed of two projections or processes: the anterior one, the so-called prepubis, or