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



Collectors' measurements of 7 adult males and 3 adult females from 

 Medje: 



Total Length Head and Body Tail Vertebra? Hind Foot Ear 



tf 575 (555-610) 310 (298-325) 267 (250-290) 43.0 (41-46) 21.5 (21-23) 

 9 603 (600-610) 323 (310-339) 284 (280-290) 41.7 (41-43) 21.5 (21-22) 



Skull, same specimens, condyloincisive length: cf, 63.8 (61.1-65.9) ; 

 9,64(63.6-64.3). 



Collectors' measurements of 5 adult males and 1 adult female from 

 Niapu : 



Total Length Head and Body Tail Vertebrae Hind Foot Ear 



& 586 (542-610) 329 (297-347) 260 (245-273) 45 (43-48) 22 (22-22) 



9 585 330 255 41 21 



Skull, same specimens, condyloincisive length: cf, 65.5 (63.8-66.5) ; 

 9 , 63.5. 



Collectors' measurements of 4 adult males from other localities (Baf- 

 wabaka 1, Gamangui 1, Niangara 2): 



Total Length Head and Body Tail Vertebrae Hind Foot Ear 



565 (550-583) 294 (279-312) 268 (260-272) 43.5 (43-44) 21.3 (20-22) 



Skull, same specimens, condyloincisive length: 64.8 (62.7-66.7). 



The above statistics indicate that there is no distinctive sexual 

 difference in size. The smallest skulls in each series are, as a rule, the 

 youngest, or skulls with full mature dentition but in which the teeth are 

 wholly unworn and the cranial sutures still distinct. There is no skull 

 young enough to show the milk dentition. In several skulls in which the 

 first molars are fully developed, the condyloincisive length is 50-51 mm.; 

 in those in which the second molars are fully up but the third molar is 

 still enclosed in the gum it ranges from 53-55 mm. ; during the develop- 

 ment of the third molar the skull length increases to about 60-61 . 5. 



Potamogale velox argens was based on two specimens, one from Medje 

 and one from Poko. As no type locality was definitely indicated, Medje, 

 the first locality mentioned in the description, is here designated as the 

 type locality. Hence the present series of 31 specimens from Medje are 

 topotypes. Poko and Niapu are both near Medje. The Niapu series of 

 13 specimens is in fine condition, the underparts being unstained, and 

 agrees in a general way with the brief description of argens; it shows, 

 however, that the white area of the underside varies in extension upward 

 on the sides and that the development of brown-tipped hairs along its 

 upper border is also a variable feature. The fore limbs are sometimes 

 "almost wholly in the whitish area" and sometimes wholly brown above 

 in specimens from the same locality and collected on the same day, show- 



