162 J. B. Hatcher — Recent and Fossil Tapirs. 



at present not distinguishable from the genus Protapirus, 

 described by Filhol from the Phosphorites du Quercy, France. 

 The species described by these authors are P. obliquidens, 

 based on a nearly complete superior dentition {No. 659 Am. 

 Mus. Col.). The authors do not give the horizon in which it 

 was found, but from the matrix enclosing it I am led to 

 believe that it is from the Protoceras beds. The other species 

 is P. simplex, based upon a series of superior premolars and 

 fragments of the lower jaw {No. 660 Am. Mus. Coll.) found 

 in the Oreodon beds. 



The Princeton Scientific Expedition of 1894 was fortunate 

 in securing material, representing a third American species of 

 this genus, besides other material which will increase our 

 knowledge of the known species of Protapirus and the some- 

 what similar genus Colodon. 



The following is given as a key to the American species of 

 Protapirus. 



1. Internal cone of all the superior premolars absolutely simple, 



showing no signs of division, with very rudimentary pos- 

 terior cross-crests, especially in pms. 3 and 4 P. simplex. 



2. Internal cone of the fourth superior premolar just commencing 



to divide, posterior cross-crests moderately developed on 

 all of the last three superior premolars P. validus. 



3. Internal cones of last two superior premolars commencing to 



divide, posterior cross-crests of the last three superior pre- 

 molars like intermediate tubercles.. .P. obliquidens. 



Protapirus validus, sp. nov. 



The type of the present species {No. 10899 Princ. Coll.) 

 consists of a nearly complete skull, without the lower jaw and 

 a complete atlas, humerus, radius, ulna and parts of other bones. 

 It is from the Protoceras sandstones, about four miles south of 

 White river and five miles below the mouth of Porcupine 

 creek in S. Dakota ; about one mile from the spot where the 

 type of Protoceras celer was secured. It was found by Mr. 

 H. F. Wells of Sturgis, S. Dakota, a most energetic collector 

 of vertebrate fossils, who was the first to distinguish the 

 Protoceras beds and the rich vertebrate fauna contained in 

 them. These beds were shown by Mr. Wells to Dr. J. L. 

 Wortman, who was the first to name and describe them.* 



In most of the more important characters, Protapirus vali- 

 dus is intermediate between P. simplex and P. obliquidens, 

 as for example, the structure of the internal cone of the sup. 

 pms., but in some respects, notably, the development of 

 the posterior cross-crests of these teeth, it is in advance 



*See Am. Mus. Bull., vol. v, pp. 95-105. 



