Of this genus we are prepared to recognize six species, which fall naturally into two groups--(A) those in which the proboscis is comparatively slightly, developed and the last lower molar is without a posterior lobe, and (B) those in which the proboscis is very long and the last lower molar, as in other Ruminants, has a third lobe. Within the groups the species differ comparatively little from each other, but may be distinguished without difficulty by the characters of size, colour, and form, used in the following synopsis:-- A. Last lower molar without a third lobe; upper line of premaxillæ slanting, scarcely curved. Proboscis less developed. _a._ Back yellowish or fulvous grey, sides scarcely more rufous. _a^1._ Size larger, basal length of skull 3·75 in. 52. _M. saltiana._ _b^1._ Size smaller, basal length of skull about 3·1 in. 53. _M. swaynei._ _b._ Back grey, sides and shoulders rich rufous or cinnamon: size intermediate between last two (skull 3·25 in.) 54. _M. phillipsi._ B. Last lower molar with a third lobe; upper line of premaxillæ =S=-shaped. Proboscis more developed. _c._ Tips of nasals about level with the front edge of the anterior premolar, about 1·3 in. from the end of the premaxillæ (gnathion). _c^1._ Back of orbit to gnathion about 3·4 in. 55. _M. damarensis._ _d^1._ Back of orbit to gnathion about 3 in. 56. _M. kirki._ _d._ Tips of nasals about level with the back of the middle premolar and about 1·65 in. from the gnathion 57. _M. guentheri._ [Illustration: THE BOOK OF ANTELOPES, PL. XXX. _Wolf del. Smit lith._ _Hanhart imp._ Salt’s Dik-dik. MADOQUA SALTIANA. _Published by R.H.Porter._] 52. SALTS DIK-DIK. MADOQUA SALTIANA (BLAINV.). [PLATE XXX.] “_Madoqua_,” =Salt=, Travels in Abyssinia, App. iv. p. xi. _Cerophorus_ (_Cervicapra_) _saltiana_, =Blainv.= Bull. Soc. Philom. 1816, pp. 75 & 79; =id.= Oken’s Isis, 1819, p. 1096.