THE SOMALI DIK-DIKS. 981 



grizzling on the back in the former, as thei^e is in the latter, and 

 the bright rufous nose-patch is not continuous with the crest, 

 which may be either rufous or dull earthy brown. 



In his ' Game Animals of Africa,' page 191, Mr. Lydekker saj^s, 

 speaking of M. swaynei, " The bucks weigh but 6 lbs. and the 

 does even less." Now it is an invariable rule among these small 

 antelopes to find the females heavier than the males. There is 

 usually a difference of 1 lb. between the sexes. Adult males of 

 Swayne's Dik-dik weigh about 4i lbs. and the females 5 or 5^ lbs., 

 whereas the average weight of a buck of M. 2)hillij)si is 5i lbs. 

 and of a doe 6| lbs. The heaviest buck of the latter species I 

 have ever weighed was 6| lbs., whereas the heaviest doe was 

 8 lbs. 



I should place the range of this Dik-dik between the 5th and 

 9th parallels of latitude, where, although it intermingles with 

 M. phillipsi, it is not nearly so common. It is quite possible that 

 it is not to be found farther north than the 8th parallel, as 

 Mr. Dodds, a friend of mine, shot a large number of Dik-diks in 

 the Ogaden Rer Ali country, especially around Daggahbur and 

 Milmil, and failed to procure a single specimen of if. sivaynei, 

 although both M. j)hilli2)si and R. guentheri were obtained. 



Madoqua piacentinii, sp. n. (PI. LVl. fig. 1.) 



Although this little Dik-dik agrees, as regards its size and 

 skull -measurements, with M. swaynei, it difiers so markedly in 

 coloration that I have considered it advisable to propose a new 

 name for it. 



In M. sivaynei the grizzling is very indistinct, being invariably 

 sufTused with a dull buff or clay colour, whei-eas in this species 

 the grey grizzling is so fine and distinct that it at once attracts 

 attention. 



The coloration of the legs in both species is similar. The 

 neck in M. 2nace7itinii is fairly grizzled all round, the pale throat 

 and buff chin patches being completely cut oif from the pinkish 

 buff of the chest. Apart from the fine grey grizzling, the most 

 distinctive patches are about the head. 



In M. piacentinii there is a bright rufous diamond-shaped nose- 

 patch which stands out conspicuously on the grizzled head, while 

 the terminal part of the long hairs of the crest in both mv 

 specimens is of a dull creamy bufi'. The hairs of the crest, 

 however, vary so much in Dik-diks that little importance can be 

 attached to this feature. The ears, which ai'e of a dark buff, have 

 a very distinct black edging on the outside, about 4 mm. in width 

 anteriorly and dwindling down to a mere edging posteriorly. 

 This peculiaritj^ I have never seen in any of the other Somali 

 Dik-diks. 



I was successful in getting only two specimens of this very 

 handsome Dik-dik, both males, but both present exactly similar 

 features. They were obtained by one of my collectors at a place 



Proc. Zool. Soc— 1911, No. LXYII. 67 



