22 



VEKTEBEATA. 



No. 56. Posbrotherium Wilsonii, Leidy. 



Skull and Lower Jaw. This specimen belonged to an individual just reach- 

 ing adult age. The form of the head, if restored, wordd probably most approach 

 that of the existing Musks. The ramus of the lower jaw is remarkable for its 

 breadth and for an angular apophysis as in the Camel, Carnivores and most 

 Rodents. The P. had three molars and four premolars in each ramus of both 

 jaws, and probably two upper canines and eight lower incisors. The original 

 was discovered in 1847, in the Mauvaises Terres (Miocene or White River Group), 

 Nebraska, and is preserved in the Academy of Natural Sciences, Philadelphia. 



Price, $1.75. 



No. 57. Oreodon Culbertsonii, Leidy. 



Skull, and Lower Jaw. This re- 

 markable Ungulate constitutes one 

 of the links necessary to fill up the 

 wide gap between existing Rumi. 

 nants and the extinct Anoplotheria. 

 The form of the cranium pro- 

 per approaches that of the Camel ; 

 but generally the skull bears most 

 resemblance to the Anoplotherium. 

 It differs strikingly from the latter 

 in the existence of post-orbital 

 arches, in the greater size of the orbits, and in the presence of deep lachrymal 

 depressions. The sagittal crest is prominent ; and the forehead is convex. The 

 molars have a ruminant character ; while canines and incisors exist in both jaws 

 and form with the molars almost unbroken rosvs. The dentition appears to char- 

 acterize a ruminating Hog. This specimen was found in the Mauvaises Terres 

 (Lower Miocene) of Nebraska, and is in the Academy of Natural Sciences, Phil- 

 adelphia. Size, 8x5. Price, $2.00. 



No. 58. Oreodon major, Leidy. 



Skull. This species differs apparently only in size. It was found in the 

 Mauvaises Terres (Lower Miocene) of Nebraska, and is in the Academy of 

 Natural Sciences, Philadelphia. Size, 11 x 7. Price, $2.00. 



No. 59. Anoplotherium commune, Cuvier. 



Head on Slab. 

 This two-toed Ru- 

 minant was about 

 the size of a Fallow- 

 JJeer. It had a long 

 and strong tail, and 

 was probably of 

 aquatic habits. It 

 was hornless, and 

 had separate meta- 

 || carpal and metatar- 

 !j sal bones. Bui it is 

 chiefly remarkable 



