O. C. Marsh—Notice of a new and Gigantic Dinosaur. 87 
Transverse diameter ssis)s5¢ cscs S25. a a aewui seta seer 
Antero-posterior diumece of distal articulation of third 
metatarsa. int seneoeiitehat Jab Genre elas sew oes 
Transverse diameters: o2c.24u un cou desig ected Leb os 
Antero-posterior epee of distal articulation of fourth 
Metatarsal os on cen cae ee Peale eee eee ee 
This specimen indicates a bird about as large as a loon, and 
apparently of similar habits. The locality of the only remains 
at present known is in Western Kansas, in the same Cretaceous 
beds that contain the Odontornithes and Pteranodontia. 
Art. XIII.—WNotice of a new and ete Dinosaur ; by 
Professor O. C. MAR 
THE Museum of Yale College has recently received from the 
Cretaceous deposits of Colorado a collection of reptilian remains 
of much interest. Among these specimens are Agog of an 
enormous Dinosaur, which surpassed in magnitude any land 
animal hitherto doovacs d. ‘The most yale bones 
preserved are portions of the sacrum, and posterior limbs. The 
former is represented by the last two vertebrae with their 
transverse processes, nearly complete, and by other fragments. 
The last sacral vertebra has its centrum moderately concave 
below on each side of the median line, but only near its ante- 
rior end can indications of a keel be observed. “The next sacral . 
vertebra has its inferior lateral surface so deeply concave as to 
materially lessen its bulk. ‘This is also true of the next ante- 
rior centrum, and may be ee, a distinctive character of 
these vertebre. A’ mo mportant character of the same 
centra is a very large eens in each side, connected with the 
outer surface by an elongated foramen, below the base of the 
neural arch. e inner surface of this cavity indicates that it 
was not filled by cartilage, and it probably was a pneumatic 
es ge ne to lessen the weight of the enormous sacral 
+ verse processes of these vertebree are very aha 
ey of mipdanas length. Their distal ends are firmly codss 
fied, forming a powerful support for the ilium. Between Chie 
processes are large oval openings. 
The following measurements ite the more important dimen- 
sions of these interesting fossils 
Length of centrum of last sacral souks aa 
Transverse diameter of distal end ........ .....------- 270° 
Vertical diameter of distal end_....__... a 
Distance between extremities of transverse processes ~<a 860° 
