846 



HISTORICAL GEOLOGY. 



Another species, more closely like Hadrosaurus, is the Didonius mirabilis 

 of Cope (1883; Trachodon mirabilis of Leidy, 1868), from the Laramie beds 

 of Dakota. The length stated is 38 feet, and that of the head, 3^ feet. 



1412. 



Dinosaur. — Triceratops prorsus (x g^g). Marsh. 



Widely different were the Herbivorous Dinosaurs of the family Ceratop- 

 sidsB of Marsh, — species of great magnitude, having the horns of cattle with 



1414 



1413-1415. 



1415 



DnsosAUKS. — Fig. 1413, Tooth of Triceratops prorsus, showing the two prongs (natural size) ; 1414, skuUof T. 

 serratus (x j'g ?) ; 1415, skull of Torosaurus gladius (^V)- Marsh. 



