0. C. Marsh— Notice of New Dinosaurian Reptiles. 248 
Creosaurus atrox, gen. et sp. nov. 
This genus is nearly allied to Dryptosaurus (Lelaps), “i 
was the carnivorous enemy of the huge Adlantosauride. It1 
indicated by various remains in oteeat ae rvation, amon " 
them the ilium represented be The teeth referred to the 
present species have the crowns more or ia trihedral, and the 
cutting edges crenulated. The metapodial bones preserved are 
me “and the terminal phalanges supported sharp claws. 
The vertebrae known are biconcave, and the terminal caudals 
are iiach elongated. 
Inferior view. Both one-tenth natural size. 
The following measurements indicate the size of this reptile : 
Antero-posterior diameter of left ilium---.--- .---------. 700™™ 
Wivtinn! Giatnatar: ee es 425° 
ngth of metatarsal - ee ee ae 277" 
Transverse diameter of proximal ‘Get ee 72° 
Transverse diameter of distal end. ------- ---- ---- ----- 79° 
Length of distal canda ees 
Transverse diameter of eer oe 2 -e e 33° 
Transverse diameter of distal end. --.--------- ---- ----- - 
This zara was about twenty feet in length. The — 
at present wn are from the same horizon as those 
described, ad were vatleatad by Mr. 8. W. Williston. 
