16 ERYTHROCEBUS 



Type locality. Go, Lake Chad. Type in British Museum. 



Color. Face brownish black, paler about eyes ; a narrow line along 

 ridge of the nose, broadening out and forming a large patch on the 

 end, black ; band across brow, and extending over temples to ears, but 

 not branching upwards to crown, black ; top and back of head rufous, 

 speckled with black on outer edge; neck and upper back extending 

 over shoulders, hairs pinkish buff annulated with cream buff, and 

 tipped with black; rest of upper parts dark orange buff, hairs annu- 

 lated with white on dorsal line and lower back, but not on rump, the 

 tips are black, the annulations, however, are more conspicuous than 

 the black tips, and give a frosted appearance to the upper parts ; rump 

 rather deeper in color than back, and without annulations towards 

 root of tail ; flanks like upper parts ; hairs below eyes on upper part 

 of cheeks, mixed black and white ; whiskers long, extending beneath 

 and beyond ears, grayish white becoming cream buff at end of hairs; 

 sides of neck cream buff ; lips, chin, throat, chest, narrow line down 

 middle of belly, forearms, hands, legs and feet, white; arms above 

 elbows on outer side covered with long black and white hairs, the black 

 predominating towards the shoulders ; sides of belly buff ; tail above 

 ochraceous rufous at base, growing paler towards the tip which is cream 

 buff; beneath white, tinged with buff at tip. Ex type British Museum. 



Measurements. Total length, 1,350; tail, 720; foot, 172, (taken 

 in the flesh). Skull: total length, 143; occipito-nasal length, 127.5; 

 intertemporal width, 47.3 ; Hensel, 98.2 ; zygomatic width, 88.5 ; width 

 of braincase, 63.2; median length of nasals, 24.8; palatal length, 49; 

 length of upper molar series, 29.8 ; length of upper canines, 28.5 ; length 

 of mandible, 99.3 ; length of lower molar series, 38.4. Ex type British 

 Museum. 



This form seems to be entitled to a distinct specific rank instead 

 of being regarded as a subspecies of E. patas. Indeed it may be said 

 to belong to a different group from that which E. patas represents, 

 that one having the legs from thighs downward pure white. The 

 type is a large, fully adult male. It differs materially from patas in 

 its grayish black shoulders instead of pale yellow, in its white thighs 

 and in the paler upper parts of body. 



Eeythrocebus circumcinctus Reichenbach. 



Cercopithecus circumcinctus Reich., Vollstand. Naturg. Affen, 

 1862, p. 123, pi. XXI, fig. 310; Pocock, Proc. Zool. Soc. Lond., 

 II, 1907, p. 745. 



Type locality. Unknown. "West Africa." 



