EDENTATA OF THE SANTA CRUZ BEDS. 



289 



series ; the centrum of this vertebra is not coosified with the second, 

 though it probably became so in the fully adult animal, and the neural 

 spine is also free, but the posterior pair of zygapophyses are fused with 

 the anterior pair of the succeeding vertebra and the transverse processes, 

 which are of lumbar type, though much longer than in any of the preced- 

 ing vertebrae, are fused with the ilia ; the absence of pleurapophyses further 

 distinguishes this vertebra from the first true sacral. The four succeeding 

 vertebras are thoroughly coossified, their spines forming a ridge which is 

 notably lower than in H. longiceps ; the first two are ankylosed with the 

 ilia and the fourth with the ischia. 



The first three caudal vertebrae are quite like those of H, longiceps, but 

 have somewhat smaller and more depressed centra and less developed 

 spines ; the spine is obsolete on the third caudal. 



MEASUREMENTS. 



Atlas, length 037 



" width 063 



Axis, length of centrum 030 



" width of anterior face 034 



" height of neural spine 046 



Third cervical, length of centrum 021 



" width of anterior face. . . .016 

 " over prezygapoph- 



yses 029 



Fourth cervical, length of centrum 020 



width of anterior face. .015 

 Anterior thoracic, length of centrum . . . .02 1 

 width of anterior face .02 1 

 " over transverse 



processes 052 



height of neural spine .042 



width of spine at base .021 



" " " " tip . .018 



Last thoracic, length of centrum 026 



width of anterior face 032 



height of neural spine. . . .052 



First lumbar, length of centrum 026 



width of anterior face 034 



Second lumbar, length of centrum 027 



" width of anterior face .. .034 



Second lumbar, width over transverse 



processes 057 



" " height of neural spine .. .067 



" " width of spine at base .. .027 



" " " " " "tip ... .026 



Third lumbar, length of centrum 029 



" " width of anterior face . . . .036 



Fourth lumbar, length of centrum 027 



" " width of anterior face .. .037 



Sacrum, length 177 



" width of anterior face 041 



" " " posterior face 036 



First caudal, length of centrum 022 



" " width of anterior face 032 



" " over transverse pro- 

 cesses 103 



Second caudal, length of centrum 022 



" " width of anterior face. . .031 



" over transverse 



processes 082 



Third caudal, length of centrum 022 



" " width of anterior face 027 



" " over transverse pro- 

 cesses 065 



? Fourth chevron, dorso-ventral height. .025 



Pelvis. The pelvis differs in several respects from that of Hapahps ; 

 the ilium has a longer and better defined peduncle and, consequently, a 



