EXTERNAL CHAUACTERS OF CHEVROTAINS. 7 



to the head, iu the development of only two supporting ridges, 

 both placed near the posterior rim, and apparently in the pre- 

 sence of the depression overlapped by lobes in the position of the 

 supratragal ridge of the normal mammalian ear. 



The Tail, as is well known, varies in length. In MoscMola 

 (text-fig. 3, A) it is vei'y short. When depressed, its tip reaches 

 the scrotum * but does not conceal it, and the scrotum is covered 

 with hair. In Trayulas (text-fig. 3, B, C) the tail igmuch longer 

 and covers the scrotum, which is naked except laterally at the 

 base. Similarly in the female tlie tail covers the genital orifice, 

 which is situated at the upper end of a lai'ge tract of naked skin. 

 In Hyemoschus the tail is at least as long as in Traguhts, but the 

 subcaudal area is not naked as in that genus but somewhat thinly 

 covered with fine white hairs. 



The Legs of the Tragulidse, as compared with those of the 

 Pecora, are remarkable for the shortness of the metacarpal area, 

 a primitive character recalling the condition seen in the Suidfe. 

 In Hyemoschus the legs and feet are relatively jtqucIi stouter than 

 in Tragulus and Moschiola, in which they are slender and delicate, 

 and in the African genus the interdigital integument forming 

 the floor of the interdigital depi'ession reaches a little nearer to 

 the heels of the hoofs than in its Oriental allies. In the three 

 genera there is a smooth pad of moderately thickened, naked 

 skin on the posterior side of the hock (calcaneal area). This pad 

 is indistinctly defined in Tragulus, but is sharply defined in the 

 other genei'a. 



In Hyemoschus (text-fig. 4, C, D) the metacarpal and meta- 

 tarsal areas are everywhere thickly covered with hairs. Those 

 on the back of the metacarpus grow downwai-ds, where^as on the 

 back of the metatarsus they grow backwards on each side, forming 

 a median crest. The back of the pasterns between the false hoofs 

 and the true hoofs is naked, except for a few hairs in the middle 

 line, and the walls and floor of the interdigital cleft in front are 

 also almost naked. 



In Tragulus (text-fig. 4, B) the metacarpal and metatarsal 

 areas are everywhere comparatively scantily haii-y, especially on 

 their posteiior sides where the hairs are so short and sparse that 

 their surfaces have been described as naked. The hairs cease 

 altogether some little distance above tlie false hoofs. Hence the 

 nakedness of the back of the pastern may be said to extend above 

 the false hoofs, a condition not observable in Hyemoschus. The 

 interdigital cleft in Tragulus is also naked to all intents and 

 purposes, as in Hyemoschus. 



In Moschiola (text-fig. 4, A) the metacarpal and metatarsal 

 ai'eas are as hairj^ as in Hyemoschus, but on the posterior side of 

 the metatarsus the hairs grow upwards from a line a little above 



* It may be noted that the scrotum iu these primitive Ruminants is sessile and 

 set high up on the perineal area just beneath the anus and is not pendulous between 

 the hind limbs as in the Pecora. Its position recalls that of the scrotum in the 

 SuidjB and Camelidse 



