sauria, or rather of that division called the Predentata, or order Ornithischia. In the other divisions, the Theropoda (Fig. 122 a) and Sauropoda (Fig. 122 b), 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.
Fig. 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 c–e) 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 pre-
