OSTEOLOd) or CA MPTOt-iA VIUJti—aiLMOlibL 



241 



base of the spine becomes less and less pronounced, only n vestige 

 remaining on the thirteenth caudal. 



From the third to the tenth the centra gradually increase in length, 

 the articular ends also undergo modifications from the vertically 

 elongated type anteriorly to the compressed medially, and to the 

 cylindroid of the posterior half, both ends of nearly all of the centra 

 being slightly concave. 



Flattened transverse processes are present on the first twelve ver- 

 tebrae counting from the sacrum. The third is believed to bear the 

 longest transverse, behind which they gradually shorten until, on the 

 thirteenth, there remains only an inconspicuous tubercle. The sup- 



1 2 



Fig. 18. — (1) Second caudal vertebra of Camptosaukus browni. Holotype. Cat. No. 

 4282. TT.S.N.M. ; \ xat. size ; side view. (2) Axterior view of same ; a. zuq, 



PREZYGAPOPHYSES ; Cf , FACET FOE FIRST CHEVRON; p, RUDIMENTARY PEG-LIKE PRO- 

 JECTION ; p. zyg, postzygapophysis ; s, neural spine ; s', neuro-cbntral suture ; tr, 



TRANSVERSE PROCESS. 



pression of the transverse process is soon followed by the disappear- 

 ance of the neuro-central suture, which becomes very indistinct. The 

 point of attachment of the transverse processes gradually moves 

 backward from the anterior lateral surface in the proximal caudals to 

 a po.stero-lateral position in those more distal. As Hatcher « has 

 pointed out in Haploeayithosaurus, so in Camptosaurus the transverse 

 processes are derived from centers of ossification distinct from those 

 which gave origin to either the centra or their spinous processes. 

 Til is fact may be considered by some as proof that these are not 

 transverse processes but perhaps might be considered caudal ribs 



'^ Mem. Carnej,'ie :\rns., II, 1903, p. 22. 

 I'loc. X. M. \(>1. xxxvi— 00 K; 



