256 



PROCEEDINGS OF THE NATIONAL MU8EU3I. 



VOL. XXXVI. 



was becoming atrophied, '\\liile this has not 3'et resulted in the 

 elimination of any of the digits, yet the fifth is fast approaching a 

 fimctionless condition. 



2Ieasitfcimnts of ijlidhnifjcs of SiJCciDirn, Cat. No. 'i.ill, V.S.N.M. 



Digits. 



Greatest length first row of phalanges 



Greatest length second row of phalanges. 

 Greatest length third row of phalanges... 



mm. 

 a 21 



mm. 

 26 

 24 

 J'48 



III. 



mm. 

 U 

 26 

 &50 



IV. 



mm. 

 26 

 a 16 

 «10 



" Measurements of elements of left forefoot of Xo. 4282, is a slightly smaller individual. 

 ^ Estimated, elements incomplete. 



THE PELVIS. 



The pelvis of Camptosaurus.^ as shown in Plates 15 and 10, is quite 

 characteristic of the genus. It is composed of the three elements, 

 the ilium, ischium, find pubis, usually found in the pelvis of the 



Fig. 29. — LErx ilium of CAMPTOSAritrs ui.siv.u M.\nsn. Cat. Xo. 5473. U.S.X.M. ; I x.\t. 

 sizK. External A'iew. End of rrBic rEDixcLE missi.vg. From a rnoTocnAi'ii. 



Dinosauria. Tlie long, slender post-pubis, reaching to tlie end of the 

 equally long shaft of the ischium, is distinctive of this group. With 

 the exception of the pubis, the parts described below are of specimen 

 Cat. Xo. 4282, U.S.N.M. 



The ilhim. — The ilium is an elongated plate-like bone, resembling 

 in most of its characteristics the corresponding element of IgiKuiodon. 

 "Jlie i)reacetabiilar process is long, narrow, and compressed laterally. 

 The ilia of this specimen lack the anterior termination, but in C. 

 <Ihpa7\ as shown by the ilium of Cat. No. 5473, U.S.N.M., the end is 

 sonicAvhat sj^atulate (see fig. 29). This long, slender process extends 

 forward and outward, overhanging the posterior ribs. The superior 

 border of the ilium is thickened and rounded transversely, and at the 

 posterior end descends for a distance of 00 mm., at an oblique angle, 

 gradually thickening to the point where it reaches the infero-internal 

 plate. Viewed laterally the ilium has a width of 87 mm. from where 

 the superior border begins to descend to the border where the inner 



