TITLES AND ABSTRACTS OF PAPERS 22'i 



NEW MOUXTS IX THE PRIXCETOX GEOLOGICAL MUSEUM 

 BY WILLIAM J. SIXCI.AIR 



[Ahstract) 



Lantern slides illustrating mounted skeletons of the Bridger Eocene creodont 

 Mcsoniix nhtusidens and the White River Oligocene cursorial rhinoceros, 

 Ht/racodon iichni.'^cvn.'ic. were exhibited. These mounts, of the most modern 

 panel type, are of interest because they embody the only practically complete 

 skeletons of both animals yet known. The material is not new. The Mesonyx 

 skeleton was found in 1SS5 and the Hi/racodon skeleton ten years later, and 

 l>oth have been described at length by Prof. W. B. Scott. The new mounts 

 bring out the highly cursorial character of these animals. In bodily propor- 

 tions. Mesonijx closely resembles a modern wolf, differing, of course, in the 

 shape of the head and in the structure of the feet, while Hyracodon ap- 

 proaches, in its limb structure, some of the larger three-toed horses of the 

 rpper Oligocene and would, undoubtedly, have been monodactyl, like the 

 modern horse, had its line persisted. 



STUDY OF THE EXTELODONTS 

 RY EDWARD L. TROXELL 



(Abstract) 



A summary of the features of several new species of entelodonts in the 

 Marsh Collection. It is argued that the wear of the teeth indicates a complex 

 movement of the mandible, and that this is made possible by the use of the 

 r»eculiar processes from the jaw and molar arch, which are so characteristic 

 of the family. 



MOUXTED SKELETOX OF MOSCHOPS CAPEXSIS BROOM 

 BY WILLIAM K. GREGORY 



{Ah at I' art) 



This dinocephaliaii reptile from the I'ermian of South Africa is repre- 

 sented in the American Museum collections by the remains of numerous skele- 

 tons, all more or less incomplete, found in one locality by Dr. Broom in 1910. 



When sorted acc<)rding to size and age by Dr. Broom, it was found that 

 three of the individuals afforded knowledge of the principal elements of the 

 adult skeleton. The missing parts of one of these have since been carefully 

 restored and the whole animal has been mounted for exhibition. Remarks 

 were made on other dinocei)haIian genera and on the characters of the group 

 as a whole. 



SMALL MAMMALS IX THE MARSH COLLECTIOX AT YALE UNIVERSITY 

 BY EDWARD L. TROXEI.L 



(Ahstract) 



Three Oligor-ene specimens of unusual interest were illustrated by lantern 

 sli<les and briefly discussed. Ilm^inodns sp.? is a very small deer with manv 



