38 Department of Vertebrate Palaeontology. 



to modern allies, as of Protorohippus to the Horse, or of Cceno- 

 pus, Metamynodon, and Hyracodon to the Rhinoceros. 



These restorations are copyrighted and the photographs are 



sold with the understanding that they are to he used only for 



exhibition pvir poses, and are not to he copied or adapted for 



publication. 



Price of the photographs, $4 each. 



I. Patriofelis, Middle Eocene Creodont. 



This animal is based upon studies of the skeleton mounted 

 in the American Museum Collection (No. 1507). The follow- 

 ing quotation from an article by Dr. Wortman explains the 

 picture: "The broad, flat, plantigrade feet, with their spread- 

 ing toes, suggest at the first glance their use for swimming. 

 The e version of the feet, together with the general clumsiness 

 of the limbs point, moreover, to the fact that the animal was 

 not an active runner. . . . He was perhaps not as expert 

 a swimmer as the seals are now, but was sufficiently active 

 in the water to capture turtles." This is perhaps the least 

 original and successful of the restorations, being modelled 

 somewhat too closely upon the Otter. More recent studies by 

 Osborn have cast much doubt upon the aquatic habits of the 

 animal as indicated by Wortman. 



Originally reproduced by Osborn in ' Prehistoric Quadrupeds of the Rockies,' Century 

 Magazine, September, 1896. 



Wortman, The Osteology of Patriofelis, Bvdl. Am. Mus. Nat. Hist., 



VI, 1894, pp. 119-64, pi. i. 

 Osborn, Oxycena and Patriofelis Re-studied as Terrestrial Creodonts, 



Bull. Am. Mus. Nat. Hist., XIII, 1900, pp. 269-279. 



2. Protorohippus venticolus, Four-toed Lower Eocene Horse. 



The studies for this animal were based upon skeleton No. 

 4832, mounted in the American Museum Collection. The very 

 primitive characters of this early stage in the evolution of the 

 Horse are especially seen in the short neck and legs, the 

 heavily muscular part of the limb extending much further 

 down in proportion to the lower leg and foot. The arched 



