THE OSTEOLOGY OF ELOTHEEJtM. 313 



theless, very much reduced. The proximal end is laterally compressed and very narrow, 

 but retains considerable ante ro-posterior extent, and bears a narrow, obliquely placed and 

 slightly convex facet for the tibia. The shaft tapers and becomes exceedingly thin and 

 delicate, though of very irregular shape ; distally the shaft thickens much in the fore- 

 and-aft diameter, but remains very narrow. The distal end forms a large external mal- 

 leolus, but continues to be very narrow. The malleolus projects inward beneath the 

 tibia and has a narrow facet which presents proximally and articulates with the facet, 

 already mentioned, on the distal face of the tibia. The astragalar facet is quite large, 

 extending for almost the whole thickness of the malleolus and curving downward in 

 front; the calcaneal facet, which occupies the entire distal end of the fibula, is narrow, but 

 has a very considerable antero-posterior extension. On the outer side of the malleolus are 

 two deeply incised sulci for the peroneal tendons. In Sus the fibula is very much stouter 

 and less reduced than in Elotherium, while the distal end is less enlarged and does not 

 extend beneath the tibia. The fibula of Hippopotamus is relatively very slender, but it 

 differs from that of the White River genus in having a smaller proximal and very much 

 larger distal end. 



L e^ 



Measurements. 



Pelvis, length 0.495 



Pelvis, antero-inferior breadth 395 



Pelvis, breadth at acetabulum 191 



Ilium, length 280 



Ilium, greatest width 197 



Ischium, length 215 



Obturator foramen, length 094 



Symphysis, length 190 



Femur, length 405 



Femur, breadth proximal end .115 



Femur, breadth distal end 100 



Femur, thickness distal end 103 



Femur, breadth of trochlea 052 



Patella, vertical diameter 107 



Patella, transverse diameter 056 



Tib'a, length 33S 



Tibia, breadth proximal end 092 



Tibia, breadth distal end 063 



Tibia, thickness proximal end OSS 



Tibia, thickness distal end 054 



Fibula, length 305 



Fibula, breadth proximal end 012 



Fibula, breadth distal end 016 



Fibula, thickness proximal end 023 



Fibula, thickness distal end 010 



