1898.] JVor/man, Extinct Cameticice 0/ North America. I 1,3 



Poebrotherium labiatum Cope. 



The type of this species consists of the larger part of a skele- 

 ton of a single individual from the White River Beds of north- 

 eastern Colorado (No. 6520). Associated with this specimen 

 are two almost complete lower jaws from the same locality (Nos. 

 6517, 6518) showing the characteristic diastemata of P . lahialum, 

 but considerably smaller. These specimens were erroneously 

 referred by Cope to P. wilsoni. I have not been able to correlate 

 with certainty the level from which these specimens were taken, with 

 that in which similar remains in the Cheyenne River region occur, 

 but judging from Cope's unpublished sketch of the section of the 

 bed, there can be little doubt that it corresponds closely with the 

 upper part of the Oreodon horizon. This surmise is strength- 

 ened by the fact that there is one specimen in the collection 

 (No. 638), from the extreme upper part of the Oreodon Bed, 

 which agrees in every way with the type of P. /af)iatin/i, except 

 that it is a little larger. Another specimen from the Cheyenne 

 River Bad Lands includes a lower jaw and a good part of the 

 skeleton. The lower jaw exhibits the characteristic diastemata of 

 P. labiatum, but is much smaller than the type, and of the same 

 size as the two jaws mentioned above. Unfortunately the exact 

 level of this specimen is not known, but it has every appearance 

 of having come from the upper [jart of' the Oreodon stratum. 



Whether or not these smaller specimens are to be referred to a 

 species distinct from P. labiatum is a matter which requires a 

 greater amount of material than we at present possess in order to 

 decide correctly. So far as one can determine at present, the 

 only distinction between the two is one of size, and this is not 

 great. 1 have thought best to regard them as belonging to the 

 same species until other differences are shown to exist. Taken 

 as a whole, P. labiatum, as exemplified by the larger individuals, 

 was considerably larger than P. wilsoni, and in the possession of 

 diastemata in the lower jaw, as well as the more caniniform 

 shape of the lower canines, makes a distinctive approach to the 

 species from the John Day Beds. In this connection it is proper 

 to observe that no remains of Camels are known from the Proto- 

 ceras level of the White River Beds. When such are found they 



[April, /Si)S. I 8 



