CHARACXEIIS OF THE SUID^, 



541 



provided beneath with two horny pads behind the nail of the 

 hoofs, constituting a pair of heels. The nails of these digits are 

 narrowed apically, flattened on the inner side, and fit together 

 like those of typical ruminant Artiodactyles. 



Except for the well-known variation in the case of Dicotyles, 

 where the fourth or outer digit of tlie hind foot is absent, the 

 inner being retained and used for scratching, the feet of the 

 difterent genera and species of Pigs are very much alike. The 

 interdigital depression is shallow, sparsely hairy, and iiot glan- 

 dular, and the back of the pasterns and fetlock to a point 

 just above the lateral hoofs is usually naked, although in 



Text-li<rurc 38. 



A. Lower view of left liincl foot of Blcotylos. 



B. The same from the side. 



C. Lower view of foot of Fhacochoerus, sliowiiig the fusion of the heels. 



an example of Sus scrofa there was a median line of hair extend- 

 ing almost down to the heels. The foot of Phacochoerus diffei'S, 

 however, from that of Dicotyles, Sus, Porcida, and Potamochcerus 

 in having the heels united ; but the degree of fusion is, I think, 

 variable, although in some cases it is very marked and practically 

 complete. Judging from dried skins, Uylochoerus has separated 

 heels like Potamochcerus. (Text-ligs, 37, 38.) 



I have fou^^d no specialized glands in the feet either of 

 Dicotyles or Phacochaerids, and with regard to the incidence of 

 the glands that have been recorded in otlier genera, further 

 information is required before definite conclusions can be reached. 



