AVillistox.] Dinosaurs. 69 



distinct groups : the Sauropoda, Theropoda and Predentata of 

 Marsh. Other names may be eventually chosen in the place of 

 these. 



The Theropoda comprise bipedal carnivorous forms of more 

 slender constructions and hollow bones, and were among the 

 earliest of the known Dinosaurs. The Sauropoda were the 

 most massive, with the fore legs only a little smaller than the 

 hind ones, and were quadrupedal in habit. They were all her- 

 bivorous and probably amphibious. Their limb bones were 

 solid. The Predentata were herbivorous in habit, and either 

 bipedal with hollow bones or more or less quadrupedal and the 

 bones solid. They included three subdivisions : The Stego- 

 sauria, with solid bones and small fore limbs, but not walking 

 erect, the body covered with large bony plates and spines ; the 

 Ceratopsia, with solid limb bones and extensive horns on the 

 head, their habit quadrupedal ; and the Ornithopoda, animals 

 resembling in form the Theropoda, but herbivorous, with solid 

 or hollow bones, and without dermal armor. 



The last of these subdivisions includes the only known form 

 from Kansas. The single Dinosaur specimen known from 

 Kansas was discovered by Professor Marsh in 1872, in the Nio- 

 brara chalk 29 of the Smoky Hill river, and named HadroMurus 

 agilis by him. 30 Allied kinds were discovered later in the Lara- 

 mie Cretaceous by Mr. J. B. Hatcher, and described by Marsh 

 under the generic name of Glaosaurus, which he proposed for 

 the Kansas species in 1890. 31 



The characters he gave for the genus are as follows : " Pre- 

 maxillaries edentulous ; teeth in several rows, but a single row 

 only in use ; cervical vertabrse opishthocoelian ; limb bones 

 solid ; fore limbs small ; sternal bone parial ; post pubis incom- 

 plete ; sacral vertebrae, nine ; femur longer than tibia ; feet un- 

 gulate ; three functional digits in manus and pes." 32 



29. It is not impossible that the horizon was Fort Pierre, since the distinction between Pierre 

 and Niobrara was not known to Marsh. 



30. American Journ. Sci., April, 1872. 



31. American Journ. Sci. 



32. Sixteenth Ann. Eep. U. S. G. S., 244. 



