212 Annals of the Carnegie Museum. 



is long and the horizontal ramus is broad, so that when the two 

 innominata are in position they form a rather wide pelvic cavity, 

 entirely unlike that of P. carrikeri. The obturator foramen is shorter 

 and not so perfectly ovate as in the Merycoidodonts generally. 



The Femur. — The femur of the type is not present. However, the 

 distal end and the greater part of the shaft of a femur belonging to 

 No. 1239 reveal some differences from P. carrikeri, i.e., the shaft is 

 more curved, the internal condyle is greater than the external, with a 

 deeper and wider groove between the two, the external border of the 

 rotular trochlea is more rounded and somewhat less produced upward 

 upon the shaft. 



The Tibia. — When compared with that of P. carrikeri the tibia is 

 slenderer; it is however short, and has the head expanded, especially 

 transversely. The spine is heavy especially on the postero-lateral 

 angle. Apparently the external facet for the articulation with the 

 femur has relatively a somewhat smaller transverse as well as antero- 

 posterior diameter than in P. carrikeri. There is a small round facet 

 for the fibula at the postero-external angle. The bone is damaged in 

 the region of the tendinal groove on the external face of the head, but 

 this groove was evidently large. The cnemial keel is very prominent 

 and extends well down on the shaft, though not so low as in Meryco- 

 choerus. Distally the tibia is expanded, but points less outwardly 

 than in P. carrikeri. The internal malleolus is not so strongly devel- 

 oped and does not point outward in the same way as in P. carrikeri, 

 Mesoreodon, and many other forms. 



Only a portion of the shaft of the fibula of the type was found. 

 It is relatively as heavy as in P. carrikeri, but is not coossified proxi- 

 mally. The distal end of a fibula is preserved with No. 1232. In this 

 the malleolus is quite heavy, the shaft rapidly contracting above. The 

 articulation for the calcaneum is as large as in Promerycochcerns 

 carrikeri and otherwise similar. 



The Pes. — The tarsus is strikingly different from that of Promery- 

 cochcerus carrikeri. The calcaneum has a shorter sustentaculum, a 

 relatively longer and slenderer tuber, the groove for the tendo achillis 

 narrower, deeper, and not oblique. There is a long, rugose, and 

 swollen area on the plantar face of the tuber, which causes an enlarge- 

 ment in the middle region of the shaft above the sustentacular facet. 

 In another specimen. No. 1239, which is referred to the same species, 

 this plantar enlargement of the middle region of the tuber calcis is 

 very much more pronounced. 



