0. C. Marsh — Gigantic Horned Dinosauria. 175 



characters with the remains of cavicorn mammals from 

 that formation, they were referred to the genus Bison, under 

 the name B. alticomis. The writer has since learned that 

 they were found in the Denver beds, which, although regarded 

 as Tertiary, are probably Cretaceous. Under these circum- 

 stances, this well-marked species may be known as Oeratops 

 alticomis, until additional remains make certain its true nature. 



Nodosaurus textilis, gen. et sp. nov. 



Another new member of the Stegosauria, from a lower 

 horizon in the Cretaceous, was discovered several years since, 

 in Wyoming, and is now in the Yale Museum. The skull is 

 not known, but various portions of the skeleton were secured. 

 One characteristic feature in this genus is the dermal armor, 

 which appears to have been more complete than in any of the 

 American forms hitherto found. This armor covered the 

 sides closely, and was supported by the ribs, which were 

 especially strengthened to maintain it. In the present speci- 

 men, portions of it were found in position. It was regularly 

 arranged in a series of rounded knobs in rows, and these pro- 

 tuberances have suggested the generic name. 



Near the head, the dermal ossifications were quite small, and 

 those preserved are quadrangular in form, and arranged in 

 rows. The external surface is peculiarly marked by a texture 

 that appears interwoven, like a coarse cloth. This has sug- 

 gested the specific name, and is well shown in the cut below. 



Dermal ossicles of Nodosaurus textilis, Marsh. Natural size. 



The fore limbs are especially massive and powerful, and are 

 much like those of the Jurassic Stegosaurus. There were five 

 well-developed digits in the manus, and their terminal phalanges 

 are more narrow than usual in this group. The ribs are 

 T-shaped in transverse section, and thus especially adapted to 

 support, the armor over them. The caudal vertebrae are more 

 elongate than those of Stegosaurus, and the middle caudals 

 have a median groove on the lower surface of the centrum. 



The animal when alive was about thirty feet in length. The 

 known remains are from the middle Cretaceous of Wyoming. 



New Haven, Conn., July 24th, 1889. 



