52 Bulletin American Museum of Natural History [Vol. XL VII 



Total Length Head and Body Tail Vertebrae Hind Foot Ear 



6 355 (346-368) 186 (183-193) 165 (163-175) 46.5 (46-48) 18.0 (17-19) 

 9 356 (348-365) 189 (181-195) 168 (160-183) 47.1 (45-49) 17.4 (16-19) 



The above measurements indicate a slightly greater size for the 

 females, as is the case also in F. pyrropus akka from about the same locali- 

 ties. 



The underparts vary considerably in the amount of buffy or ochrace- 

 ous wash on the ventral surface, independently of season or locality, the 

 palest being nearly white and a few (four out of twenty-eight) closely 

 approaching the average of the Niapu series of twenty-two described 

 below. 



Funisciurus anerythrus niapu, new subspecies 



Type, No. 50877, c? adult, Niapu, Belgian Congo, November 9, 1913; Herbert 

 Lang and James P. Chapin, Orig. No. 2120. 



Similar to typical anerythrus, but underparts averaging much darker and more 

 ochraceous, the ochraceous tips of the hairs being longer and brownish ochraceous, 

 often wholly concealing the dark basal portion of the pelage. 



Collectors' measurements of the type: Total length, 359 mm.; head and body, 

 190; tail vertebrae, 169; hind foot, 47; ear, 18. 



Skull (type): Greatest length (=occipito-nasal), 45.7; condyloincisive length, 

 40.7; least interorbital breadth, 11.7; tip to tip of postorbital processes, 19.2; post- 

 orbital breadth, 16.1; breadth of brain-case, 20.1; zygomatic breadth, 25.5; length 

 of nasals, 12.2; breadth of nasals anteriorly, 4.6, do. posteriorly, 5.9; length of 

 maxillary toothrow, 8.1. 



Represented by 24 specimens collected as follows : 



Niapu, 22 (10 d\ 12 9 — 3 tf and 4 9 immature) all collected November 9-30, 

 1913, except one taken at same locality a month later (December 25). 



Stanleyville, 2 (d\ 9 in alcohol), September 6, 1909, January 18, 1915. 



Collectors' measurements of 13 adult specimens from Niapu (6 males, all adult; 



7 females, of which 3 are young adults) : 



Total Length Head and Body Tail Vertebrae Hind Foot Ear 



& 356 (337-390) 195 (181-226) 162 (155-169) 45.7 (45-47) 17.3 (17-19) 



9 350 (340-364) 199 (178-205) 163 (157-165) 46.0 (45-47) 17.3 (16-18) 

 Skulls, same specimens : 



Greatest Length Zygomatic Breadth 



tf 46.5 (43.6-49.0) 25.7 (24.7-26.7) 



9 46.9 (44.9-49.7) 25.2 (24.4-26.3) 



It is clearly evident that the marked difference in the coloration of 

 the underparts, which alone distinguishes strongly the Niapu specimens 

 from all of those from the other six localities to the eastward, is not 

 seasonal rather than geographic, the fact being that the greater part of the 

 adults from the other localities were taken at the same season (most of 

 them during the same month) as those from Niapu. A series of five from 



