290 



PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxvi. 



Hypsilophodon and of the North American Camptosaurus (Camptonotus), and 

 differs from that of Iguanodon In its markedly forward arcuation. The inner 

 trochanter has lost its free extremity, but the basal portion shows that it is of the 

 " pendant " type characteristic of the two former genera and not the " crested " 

 type found in Iguanodon. The anterior intercondylac groove is slightly less 

 developed in this specimen than in either of the Wealden genera, but it is still 

 present. * * * There is, indeed, no decisive evidence to prove that the 

 present specimen indicates a form specifically distinct from the species from 

 the Kimeridge Clay [C. (Iguanodon) prestwichn'\ ; but since most of the 



Sauropterygians of the Kimeridge are distinct 

 from those of the Oxford Clay, I think it highly 

 probable that the same may hold good with the 

 Dinosaurs, and I therefore propose to provision- 

 ally regard the present specimen as the repre- 

 sentative of a distinct species which may have 

 been somewhat smaller than Iguanodon prest- 

 ivichU, * * * jjj^^i since I can see no char- 

 acters by which either this specimen or /. prest- 

 wichii can be separated from Camptosaurus, I 

 propose to refer both the Kimeridgian and Ox- 

 fordian species to that genus under the respec- 

 tive names of C. prcsticicJiii and C. Iccdsi. 



While the femur of C. leedsi, as de- 

 scribed and figured by Lydekker, appears 

 similar in most respects to the femora of 

 the American Camptosaurus, yet the posi- 

 tion of the inner trochanter wholly upon 

 the proximal half of the shaft (see fig. 44) 

 at once distinguishes it from all of the 

 described species of that genus, which in 

 all cases show this trochanter extending 

 somewhat below the median line. That 

 C. leedsi represents a closely related form 

 there can be no question, but, if referable 

 at all to an American genus, its closest 

 affinities, as indicated by the femur, are 

 with Dryosaurus. This suggestion be- 

 comes more apparent when it is known 

 that a recent examination of the type 

 specimen of D. alfiis, No. 1876, Yale 

 Museum, shows that the femur has been 

 incorrectly illustrated. For example, the shaft is not straight, but 

 is curved as in Camptosani'iis., and while the inner trochanter is 

 upon the proximal half, it is not placed so high as indicated in 

 the figure." The femur of C. leedsi may be distinguished from the 

 femur of Ilypsilojjhodon by the " more wing-like " shape of the 

 inner trochanter of the former. 



Fig. 44. — Left femur of Camp- 

 tosaurus LEEDSI Lydekker ; 

 FROM THE Oxford Clay near 

 Peterborough. 5 nat. size. 

 HoLOTYPE. a, head ; h, les- 

 ser TROCHANTER ; C, INNER 

 TROCHANTER ; d, INTERCON- 

 DYLAR GROOVE ; e, INNER CON- 

 DYLE. After Lydekker. 



"Amer. Journ. Sci., XVI, 1878, pi. ix, fig. 3. 



