lo8 Bulletin American Museu?n of Natural History. [Vol. X, 



distinct facets, but in the last two the capitular and tubercular 

 facets appear to be fused together as in these dorsals of the Llama. 

 The lumbars are seven in number, the constant formula for the 

 Tylopoda ; they resemble closely the corresponding bones of 

 Pocbrotheriuin and the later Cameloids. The sacrum is composed 

 of only four vertebrce, but it is highly probable that another one 

 or two was added from the caudal region as age advanced, just as 

 in Poebrotherium and the modern Llamas. The three anterior 

 vertebrae of the sacrum have very reduced neural spines, while in 

 the fourth the spine is well developed. The ribs do not display 

 any characters of especial importance. 



The pelvis is in a very fragmentary condition, but it may be 

 stated that the ilium is well expanded, and, so far as one can 

 judge, the whole l)one would correspond closely with that of 

 Poebrotherium. The femur is present in its entire length with 

 both ends in a good state of preservation, although the shaft is 

 somewhat crushed. The proximal end has practically the same 

 relations and arrangement of the different parts as that of Poebro- 

 therium and other members of the group. The distal end thus 

 early gives slight though conclusive evidence of the peculiar and 

 characteristic appearances which this part of the bone assumes in 

 the later Camelidiie. This is especially seen in the great extension 

 of the condyles backwards behind the median line of the shaft 

 as well as the forward projection of the borders of the rotular 

 groove, which serve to increase the antero-posterior diameter of 

 this part of the bone. Although not clearly indicated on account 

 of crushing, yet there seem to be distinct traces of the beginning 

 of that peculiar depression at the proximal end of the rotular 

 groove so highly characteristic of the later Tylopoda. In a like 

 manner the patella has begun to assume the distinctively cameloid 

 form by the great elongation of its lower border into a long, 

 pointed process. 



The tibia, which about equals the femur in length, shows a 

 great resemblance to that of Poebrotlieriuiii. Tlie cnemial crest 

 is unusually well developed, and extends quite one-third of the 

 way down the shaft. The fibula is much reduced, and although 

 the specimen does not show whether or not the shaft was com- 

 plete, the probabilities are that it consisted of a distal ))ortion 



