34 



BULLETIN 110, UNITED STATES NATIONAL MUSEUM. 

 Measurements of axes, Antrodemus valens. 



Greatest length of centrum 



Greatest width of anterior extremity . 

 Greatest width of posterior extremity 



Greatest height over all 



Least width of centrum 



No. 4734. 

 U.S.N.M. 



Cervicals posterior to the axis. — All of the cervicals posterior to the atlas and 

 axis were found disarticulated, but the complete series was recovered and in an 

 excellent state of preservation. 



Fig. 18. — Articulated cervical vertebrae of Antrodemus valens Leidt, No. 8367, U.S.N.M. Viewed from the right 

 side | nat. size, ax, axis; ax. in, axis intercentrum; o, odontoid; 3, 4, 5, 6, 7, S, 9, cervical vertebrae three to 



NINE RESPECTIVELY. 



In all, counting back from the skull there were nine vertebrae and these prob- 

 ably represent the entire cervical series as corroborated by specimen No. 8367, 

 U.S.N.M., shown in figure 18. The remaining 14 presacrals were found articulated. 

 This specimen therefore is in perfect accord with No. 666 of the American Museum 

 of Natural History, New York, which has 23 vertebrae in the complete presacral 

 series. 



The third cervical may be distinguished by the sharp longitudinal keel on the 

 ventral side of the centrum, all others including the atlas and axis, having this 

 portion of the centrum smoothly rounded. 



