Zoological Society. 



295 



galus (a), is the distal epiphysis of the fibula, and the sole represen- 

 tative of that bone. The astragalus and calcaneum conform to the 

 ordinary Ruminant type ; according to which, also, the naviculare (s) 

 and cuboid (6) are confluent. The ectocuneiform (ce) is a broad flat 

 bone supporting the moiety of the cannon-bone which answers to 

 the digitus medius (m) : a small round sesamoid (5) at the back of 

 this joint has not sufficiently distinctive characters to carry convic- 

 tion as to its special homology. The outer half of the cannon-bone, 

 or metatarsal of the fourth toe (iv), articulates with the cuboid part 

 of the scapho-cuboid bone. The second digit (ii) and fifth digit (y) 

 are represented solely by the rudiments of their middle and ungual 

 phalanges (2 & 3). There are two large trochlear sesamoids (s) 

 behind the metatarso-phalangeal joints of the two fully- developed 



Fig. 1. 



Fig. 2. 



Bones of fore-foot {Bison europcms). Bones of hind-foot {Bison europcBus). 



toes {iii & ev), and one sesamoid behind the last joint of the same 

 toes. 



In most artificially-prepared skeletons of Ruminants, more or less 

 of the small bones, often regarded as accessory, are lost ; but they are 

 really for the most part beautifully indicative of traces of adherence 

 to the archetype, and I have on that account particularized them in 

 this notice of the anatomy of the Aurochs. 



