516 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 92 
and feet, entirely comparable with characters indicated for Z’anupo- 
lama. The type, U.S.N.M. No. 10166, an incomplete posterior cannon 
bone, measures about 44 by 40 mm. at the proximal end, a somewhat 
smaller diameter than the figures given by Stock for 7’. stevensi, 
and the incomplete length is about 290 mm., approximately two-thirds 
the entire bone. The distal portion of a radius-ulna is also seen to 
be of slightly less diameter than this element in 7’. stevensi as measured 
by Stock. A number of foot bones in the Anita collection represent 
T. longurio; however, two broken portions of the distal end of a 
cannon bone, No. 10174, which Hay indicated as belonging to this 
species, probably belong to the larger camel in the fauna. 
Compared with material of Zanupolama stevensi (Merriam and 
Stock)** the fourth premolar in the Curtis ranch specimen appears 
slightly smaller but the molars are seen to be appreciably longer 
anteroposteriorly and relatively narrower than those for which 
dimensions are given. Although the anteroposterior length of the 
occlusal surface of the teeth would change appreciably with wear, 
possibly not enough to account for the difference in size of teeth 
between the Curtis ranch form and that from McKittrick tar pits. 
The lingual walls of these teeth though moderately smooth appear 
less so than in 7’. stevensi and the anterointernal style on M; seems more 
outstanding than in the figured material of 7. stevenst. Another 
character noted, but possibly not of importance, is the higher position 
of the process of the angle on the posterior border of the ramus from 
Curtis ranch. Zanupolama stevensi is probably distinct from 7’. 
longurio, as the remoteness of the late Pleistocene stage at McKittrick 
from the earlier horizons at Curtis ranch and Anita would suggest, 
even though the geographic separation is not great. 
The type of Zanupolama americana (Wortman)*’ from the Pleisto- 
cene at Hay Springs, Nebr., a stage also later than that at Curtis ranch, 
has an apparently shorter cheek tooth series and the portion of the 
jaw anterior to P, seems significantly longer than in the Curtis 
ranch jaw, although these differences could be accounted for in part 
by the difference in maturity between the two individuals. In 1929 
Frick *® proposed the name Prochenia for Wortman’s species, but 
this must be regarded as a synonym of Zanupolama. 
The type lower teeth of Tanupolama mirifica Simpson *° from the 
Seminole field in Florida are in nearly the same stage of wear as 
those in the Curtis ranch jaw but measure a little shorter anteroposte- 
4° J. C. Merriam and Chester Stock, Carnegie Inst. Washington Publ. 347, pp. 37-42, figs. 
1-4, 1925, 
47J. L. Wortman, Bull. Amer. Mus. Nat. Hist., vol. 10, art. 7, pp. 133-134, fig. 21, 1898. 
48 Childs Frick, Nat. Hist., vol. 29, p. 107, 1929. 
49G. G. Simpson, Bull. Amer, Mus. Nat. Hist., vol. 56, art. 8, pp. 593-596, figs. 17-19. 
1929. 
