Douglass : Vertebrates from Montana Tertiary. 



165 



nasals do not contract so gradually to the apex ; and judging by Cope's 

 fi<nire,' they are longer; the posterior pointsof the premaxillaries do 

 not approach so near to the anterior projections of the frontals, the 

 former being short fore 

 and aft. The tympanic 

 bulU^ are smaller. The 

 antemolars are less spaced; 

 the incisors are crowded. 

 According to Cope's figure 

 V^, P^, and pi, exclus- 

 ive of the heel, are wider 

 but of the same length. 

 The heel on P^ and the 

 deuterocone on the sec- 

 torial are not so well de- 

 veloped ; M- is much 

 larger, the great differ- 

 ence being in the antero- 

 posterior diameter. 



Comparison with Cr/io- 

 desmiis thooides. 



The anterior part of the 

 skull is lower and nar- 

 rower ; not so broad at the 

 post-orbital angles of the 

 frontals but broader at the 

 post-orbital constriction ; 

 the, temporal ridges con- 

 verge less rapidly; the pre- 

 maxillaries and frontals do 

 not api^roach so near each 

 other ; the premolar teeth 

 are smaller, much lower, 

 and all except thefirst are 

 shorter. The deuterocone 

 on P-*- is less prominent ; 

 the transverse diameter of 

 the molars is less. 



'Tertiary Vertebrata, PI. LXXI. 



:^ o 

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