1922] Allen, Congo Sciuridse, Anomaluridae, Idiuridae, 55 



Collectors' measurements of 13 youngish adults from Niapu (5 

 males, 8 females) : 



Total Length Head and Body Tail Vertebrae Hind Foot Ear 



d* 337 (317-355) 186 (176-201) 151 (141-159) 47.6 (47-48) 18.2 (18-19) 

 9 349 (322-371) 189 (165-206) 160 (145-173) 47.6 (45-49) 17.5 (16-18) 



Skulls, same specimens: 



Greatest Length Zygomatic Breadth 



c? 46.2 (45.4-48.1) 25.5 (24.7-26.2) 



9 45.7 (45.2-47.9) 25.4 (25.0-26.8) 



Only three of the thirteen Niapu specimens of which measurements 

 are given above are old adults (1 cf , 2 9 ) , as indicated by the condition 

 of the teeth and sexual organs (scrotum present in the male, mammae 

 Conspicuous in the females) ; in the other ten the dentition is complete 

 but the teeth are unworn or only slightly worn, and no mammae are 

 distinguishable in the females. The measurements below of thirteen 

 specimens from other localities (all that are available) include only 

 adults of middle age or older, and thus average, as would be expected, 

 larger than the Niapu series, which consists almost entirely of rather 

 young adults. 



Collectors' measurements of 13 specimens (6 males, 7 females, all 

 middle aged or old) from other localities (Akenge, Avakubi, Boyulu, 

 Ngayu, 1 each; Niangara, 2; Gamangui, 3; Medje, 4): 



Total Length Head and Body Tail Vertebrae Hind Foot Ear 



d 1 335 (322-351) 190 (184-208) 148 (136-156) 48.5 (48-49) 18.7 (18-20) 

 9 344 (317-340) 193 (187-202) 151 (130-161) 47.0 (46-48) 18.4 (18-20) 



Skulls, same specimens: 



Greatest Length Zygomatic Breadth 



d* 47.5 (46.4-48.5) 25.7 (24.9-27.1) 



9 47.9 (46.4-48.5) 26.3 (24.9-26.7) 



The above measurements of two series of specimens, totaling li 

 males and 15 females, indicate that the females are slightly larger thari 

 the males, but the difference is too small to be diagnostic. 



The thirty-two specimens of F. p. akka are exceedingly Constant iri 

 coloration, season and age making very little difference in this respect: 

 The underparts, including the inside of bdth fore and hind limbs, are' 

 pure white to the base of the fur. Immature and September-November 

 adult specimens show a tendency to a faint pinkish wash on the inside of 

 the hind limbs and (exceptionally — in two or three specimens only) on 

 the middle of the belly. The pale buff lateral line running from the 1 

 shoulder to the hip varies little in color, but is much better defined iri 



