NO. 1666. OSTEOLOGY OF VAMPTOSAVRUS—GILMORE. 259 



pubis. The anterior portion is a thin, flat, vertical Wade of bone, 

 ^Yhen articulated extends forward, downward, and slightly outward. 

 The superior border is gently concave antero-posteriorly, and near 

 the proximal end expands transversely into a triangular, roughened 

 surface for contact with the pubic peduncle of the ilium. The 

 proximal end is expanded transversely, forming a heavy, concave 

 end Avhich bounds part of the anterior and inferior borders of the 

 acetabulum. 



The lower part of the proximal end has a rugose surface for con- 

 tact with the antero-infero projection of the proximal end of the 

 ischium. On the lower internal border of the proximal end the post- 

 pubic bar is developed, which extends backward and downward be- 

 neath and parallel with the ischium, reaching to the end of that bone. 

 Between the anterior end of the postpubis and the posterior acetabu- 

 lar surface of the prepubis is a large pubic foramen, which, in some 

 individuals at least, does not appear to have been entirely closed 

 posteriorly. While the notch -is closed in three individuals studied, 

 the union of the two surfaces is not to coalescence, the suture in all 

 instances being visible. 

 Posterior to the up- 

 ward projection of the 

 superior surface of the 

 postpubis is a shallow, 

 roughened depression 



which was in contact 



. Fig. 32. — Left ruBis of Camptosaurus dispar Marsh. 



With the lower anterior paratypb. no. is78, yale museum ; a nat. size. 



prolono-ation O f t«h e external view, p, pubis ; p', postpubis. After 



7 , . ^^ Marsh. 



ischium. A cross sec- 

 tion at the broken end of the postpubis of Cat. No. 4282, U.S.N.M., 

 shows it to be subcircular in outline. The distal end is slightly ex- 

 panded, esi^ecially in the ventral direction. In No. 1880, Yale Mu- 

 seum, holotype of C. medius, in which this element is complete, the 

 postpubis is 480 mm. in length. Its distal end is 23 nun. wide in the 

 vertical direction. 



The anterior ends of the pubes do not meet medially. 



THE HIND LIMB. 



The hind limb and foot in Camptosaurus is about twice the length 

 of the fore limb and foot and much more robust. The tibia is 

 slightly shorter than the femur. There are four ossified elements in 

 the tarsus, the calcaneum and astragulus being distinct. 



The femm\ — Unfortunately the femora are lacking in Cat. No. 

 4282, U.S.N.M., but in a second, larger individual both are present, 

 and two more, representing as many individuals, were found in the 

 collection. All are remarkably free from distortion, and in a fine 

 state of preservation. The description to follow is based upon the 

 femora of No. 5818 (see fig. 33). 



