KO. 1CG6. 



OSTEOLOGY OF CAMPTOSAURVS—OILMORE. 



283 



the scapula. In the type-specimen the coracoid and scapula were not 

 coossified. (See fig. 40.) 



The humerus lacks the robust development of the deltoid crest and 

 the articular ends are not so rugose as in the larger species ; in other 

 respects they appear identical (compare figs. 25, 2G, and 41). 



The ulna (see ul^ fig. 41) appears to be more curved than the ulnse 

 of either C. hrowni or C. dispar^ but in the triangular contour of the 

 proximal end it approaches the latter species. The radius shows no 

 important differences. 



Both of the ilia were recovered and, as found, were not far removed 

 from their normal position in relation to the sacrum, as shown in 

 fig. 39, the left one being the more com- 

 plete. In its general proportions it 

 approaches the ilium of C. (Lis par (see 

 Plate 14, fig. 2) rather than the narrow 

 and more depressed ilia of either C. 

 medius, C. browni, or C. depressus, al- 

 though the anterior termination of the 

 preacetabular process is especiall}^ like 

 that of the latter species. The ace- 

 tabular notch is deep and the ischiac 

 process robustly developed, and there 

 is a Avide horizontal plate or shelf on 

 the inner side of the posterior portion, 

 as in the larger species. The pubic 

 process is directed forward and well 

 downward, thus giving good w^dth to 

 the preacetabular notch. 



The ischia of C. nanus lack their dis- 

 tal ends, but a comparison of the re- 

 maining parts with those of the larger 

 species shows no especial differences. 

 The portion of a pubis pertaining to 

 the type is too mutilated to allow of accurate comparison, although it 

 shows that a postpubic process was j^resent. 



Except in their very much smaller size, a critical comparison of 

 the elements of the hind limbs of C. nanus with those of C. dispar 

 failed to reveal any essential differences. Ossified tendons still ad- 

 hering to the vertebrae, and particularly to the sacrum, were found 

 in the matrix (see g. t, fig. 39). 



After a careful review of the typical material, as compared with 

 the other species of this genus, I find that C. nanus may now bo 

 characterized as follows: 



Specific characters.— Typically of small size. Coracoid short, 

 quadrangular in outline. Sacral vertehrm without peg-and-notch 

 articulation. 



Pig. 41. — Right iiumekus, e-vdius 



AND fLX.V CAMPTOSAUKUS NANUS 



Marsh. Cat. No. 2210, U.S.N.M. 



HOLOTYrE. J NAT. SIZE. ll, HU- 

 MERUS ; ra, radius ; ul, ulina. 

 From a photograph. 



