57 



Char, specif. — The largest fragment of a long bone is probably from the 

 proximal end of the tibia ; it includes the curved border of the inner side, and 

 the inner posterior tuberosity, with five inches of the inner side of the shaft. 

 The superficial layer is marked with numerous closely-placed longitudinal 

 grooves, which are replaced at intervals by a few coarser and deeper ones, 

 which interrupt the angle with the articular surface, giving it a lobate margin. 

 There was probably a prominent cnemial crest. Another fragment exhibits 

 one flat plane, and a concave posterior face. It comes from near the extremity 

 of the humerus or the femur ; it was found near the fragment of the tibia. The 

 sacral vertebra is probably that of an animal not fully grown, as it was not co- 

 ossified with those adjacent. The articular extremities are expanded, and pre- 

 sent distinct faces for articulation for the large diapophyses. The one extremity 

 is more expanded and less thickened, the other more thickened and less 

 dilated ; on this rests the greater part of the base of the neural arch. Just 

 at the extremity of this base, the large sacral nervous foramen issues, which 

 is continued in a wide groove downward between the transverse expansions. 

 Inferior surface convex. As compared witli the fourth sacral vertebra of 

 Agathaumas sylvestris, Cope, which it nearly resembles in size, it is to be 

 observed that the anterior extremity is less expanded transversely as compared 

 with the posterior ; that the bases of support for the anterior diapophyses are 

 not produced downward so far; that the sides of the centrum are nearly ver- 

 tical, and not sloping obliquely toward the middle line ; and that there is no 

 inferior plane separated from the lateral by a longitudinal angle, as in A. 

 sylvestris. It differs in like manner from the third and second sacral verte- 

 brae, and still more from the first of the latter saurian. 



Measurements. 



M. 



Length of the centrum of the fourth sacral vertebra 0. 092 



Transverse diameter: 



In front 0.103 



At middle 0.072 



Posteriorly 0. 121 



Vertical diameter, posteriorly 0. 092 



Diameter of tho head of the tibia, antcro-posteriorly 0. 250 



CIONODON, Cope. 



Bulletin of the United States Geological Survey of the Territories, No. 1, 1874, p. 2. 



Remains of species of Dinosauria were obtained at two localities in 

 Colorado, not many miles apart ; the greater number at one of them, from 

 8 c 



