CREODONTA. 371 



deeper than wide, and is convex anteroposteriorly and concave transversely. 

 Its internal part is reverted to the inferior side, no doubt to accommodate 

 the posterior process of the navicular. The general appearance of this 

 double articulation is much like that of a perissodactyle ungulate. The 

 trochlea is wider and not so convex nor so deeply grooved as in M. obtiisi- 

 dens. It is hour-glass shaped, and the external face has considerably greater 

 extent than the internal. The former is vertical except the anterior part, 

 which descends as an angular process into a fossa in front of the calcaneal 

 condyle, which is flared outwards. An articular band marks the inner face 

 of the trochlea continuous with the general surface. The postero-intemal 

 angle is produced, as in Oxyoena, into a flat subhorizontal rounded process, 

 which overhangs the sustentaculum. The neck of the astragalus is much 

 shorter than in M. obtusidens. The posterior outline is widely and deeply 

 notched. 



The calcaneum is long and rather narrow. The sustentaculum and 

 the superior condyle are both small. Below the lattei', on the external face, 

 is a strong longitudinal crest continuous to the cuboid face. This crest in 

 Oxycena and in carnivora stops at or before the vertical line of the anterior 

 end of the condyle. Beneath it the side of the calcaneum has a deep longi- 

 tudinal concavity. The free extremity is truncate. The cuboid surface is 

 large, but imperfection of the specimen obscures its external boundary. It 

 is flat and not very oblique to the axis of the bone. 



Measurements of tarsus. 



Length of astragalus ou inner side 044 



Lengtli of internal arc of trochlea 024 



Length of external 031 



Depth of inner side at trochlea 023 



Length of neck of astragalus 015 



Anteroposterior diameter of distal end 022 



Diameters navicular facet ^°''''1"« ^^* 



( transverse 016 



Diameters cuboid facet J "•'1'1«« ^^ 



I transverse 007 



Length of calcaneum 077 



Depth at free extremity 027 



Depth at condyle 034 



Depth at cuboid facet 026 



Width at free end 022 



Width at sustentaculum ,,. , 041 



Depth (vertical) of cuboid facet 023 



