138 DINOCERATA. 



m. 



Vertical diameter of anterior face of first sacral, 072 



Length of centrum of first sacral, 085 



Length of centrum of second sacral, . . . .075 



Length of centrum of third sacral, - . 065 



Length of centrum of fourth sacral, . — .067 



The Caudal Vertekr.e. 

 (I'late XLIII ; and woodcut 136, below.) 



The anterior caudal vertebni? of the JDinocerafa have the centra short 

 and Hat, witli loiiy and depressed transverse processes. The neural spine 

 is only moderately developed. The neural arch is low, and situated on 

 the anterior two-thirds of the centra. The zygapophyses are weak, and 

 their articular faces usually curved. 



In the median eaudals, the transverse processes become shorter, and 

 gradually disappear. 



The distal eaudals are cylindrical, and of moderate length. They 

 are without zygapophyses, or neural arches, as seen in figure 136, below. 



FlGDRE laC— Cau(l:il \erlebra of Dinoceras lotkeps, Marsh (Xo. Ui::9). 

 a, prozimal end; b. side view; c. illslal end. 



All the figures are one-half natural size. 



The under surface of the caudal vertebrje is rugose, and there are 

 no chevron bones. 



