1900.] FROM NORTH-EASTERN AFRICA. 801 



and in addition a number of native furrier's skins, all of which 

 agree with the type in the light colour of their tails. The good 

 male skin has the blackest tail of all, and is evidently exceptional 

 in this respect, but it has still far less black than the Abyssinian 

 examples. Had it not been for this variation, however, I should 

 have been disposed to call the Omo River Colobusa, distinct species, 

 as has been done with the other East-African forms of the genus. 



2. Cercopithecus butoyiridis G-eoffr. 



a. Juba E., 2 Oct., 1899. 



b. Webi Dawa. 



c. Omo E., 21 Dec, 1899. 



3. Cercopithecus omen sis, sp. n. 



a. 2 ■ Mursu, Omo Eiver, about 40 miles X. of Lake Eudolf. 



Allied to C. albigularis, but very markedly smaller, and without 

 the yellowish infusion in the dorsal colour. 



Head and bnck clear grizzled grey, the former without the 

 brownish and the latter without the yellowish or rufous tone 

 found in the allied species. Crown, centre of nape, and withers 

 blackish. Lips, chin, throat, and sides of neck dull white. Hairs 

 on ear also white. Whole of arms and legs uniformly black. 

 Hairs round anus rufous. Tail black, grizzled proximally with 

 white. 



Skull, as compared with that of C. albigularie, markedly smaller 

 and lighter. Upper outline more convex. Nasal opening small. 

 Face particularly narrow, as shown by the measurement across 

 the orbits. Teeth small and delicate, less in every dimension 

 than those of the allied species. 



Dimensions of the skull, that of a fully adult female, with all 

 the teeth worn: — 



Greatest length 87 mm.; basal length 64; zygomatic breadth 57; 

 least breadth of face across outside orbits 46 ; breadth of nasal 

 opening 9 ; combined length of upper premolars and molars 22*3 ; 

 the same below 26. The flat skin measures approximately, head 

 and body 440, tail 480. 



Type. Female. B.M. No. 0.11.7.7. Original number 128. 

 Collected 29 Dec, 1899, and presented by Dr. Donaldson Smith. 



This little representative of the common East-African C. albi- 

 gularis may be readily recognized by its much smaller size and 

 less yellowish coloration. C. stuhlmanni, Matsch., is as large as 

 C. albigularis. 



4. Cercopithecus neglectus Schl. 



a,b. $ . Omo Eiver,. 23 Dec, 18.99. (124, 126.) 

 This interesting Monkey, almost a topotvpe of the species, proves 

 to be quite similar to a West-African skin of Cercopithecus brazzce 

 M.-Edw., and thus confirms the suppression of the latter name as 

 being merely a synonym of the former. 



