60 Annals of the Carnegie Museum. 



Transverse diameter of calcaneum at sustentaculum 41 



Greatest height of astragalus 53 



Greatest transverse diameter of astragalus 46 



Moropus elatus Marsh. 22 



Professor Marsh based his description of this species 23 upon a few 

 foot bones. Since then but little additional material was found until 

 the fortunate discoveries recently made by the field parties of the Car- 

 negie Museum, and especially by Mr. W. H. Utterback in the Agate 

 Spring Fossil Quarry during the present season. These important 

 discoveries will, it is hoped, give us much welcome information in 

 regard to this highly interesting animal. Mr. Utterback reports find- 

 ing a great many vertebrae, ribs, limbs, and foot bones of one indi- 

 vidual, besides numerous lower jaws, parts of limbs, and isolated 

 bones, in the Agate Spring Fossil Quarry. The material is unfortu- 

 nately as yet only partially prepared for study and description. 



The specimen, No. 1424, was found near the base of the Upper 

 Harrison beds on the Niobrara River in Sioux County, Nebraska, in 

 1 90 1. The specimen consists of the radius, ulna, and part of the fore 

 foot, the femur, the left tibia nearly complete, and part of the right 

 tibia, a fragment of the fibula, the calcaneum and astragalus of both 

 hind feet, and a few phalanges. The important question of the 

 relative lengths of the fore and hind limbs is settled by this specimen 



As in Chalic other ium {^Ancylotherium) pentelici (Gaudry), the ole- 

 cranon process of the ulna is short and heavy. Distally the radius and 

 ulna are coossified, 24 and the two bones are rather slender and are very 

 much elongated. The general shape of the carpus is similar to that 

 in Macrotherium giganteum Gervais, but is not nearly so heavy. On 

 the ulnar side of the scaphoid, at the distal end is a heavy and rounded 

 process, which reaches over and articulates with the magnum in a 

 similar manner to that in Macrotherium giganteum. The articulation 

 for the scaphoid on the magnum is, however, more lateral in the latter 



22 Professors Cope and Scott have regarded Moropus as synonymous with Chalico- 

 therium, while Osborn (Am. Naturalist, February, 1893, p. 122), regards Moropus 

 as synonymous with Macrotherium, but recent study of the material collected by the 

 parties of the Carnegie Museum reveals the fact that Moroptts elatus is generically 

 separable from these European genera. 



23 Am. Jour. Science (3), Vol. XIV., pp. 249-250, 1877. 



24 A large individual, No. 1604, from the Agate Spring Fossil Quarry, has the 

 radius and ulna coossified throughout. 



