1922] Allen, Congo Collection oj Insectivora 7 



ing this alleged distinction to be subject to a wide range of individuality. 

 Specimens taken at approximately the same date vary greatly in the 

 condition of the pelage in respect to wear, but, on the whole, December 

 specimens, taken near the close of the dry season, appear more worn than 

 those taken in March-May, the rainy period. But doubtless the season 

 of moult varies in different individuals and, like the birth of the young, 

 may extend over a considerable part of the year. 



Only two forms of Potamogale, in addition to the original P. velox 

 Du Chaillu, appear to have been distinguished. These are P. allmani 

 Jentink (1895), based on Allman's detailed description (loc. cit.) of a 

 specimen preserved in spirits from Old Calabar, published some twenty- 

 six years before. The second, P. velox argens Thomas, was added in 

 December 1915, on the basis of two specimens from the Upper Congo. 

 The large series of specimens collected by the American Museum Congo 

 Expedition demonstrates that the characters relied upon for the discrim- 

 ination of these two forms are without value and, for this reason, are 

 subjected to comment. 



As shown in the collectors' field notes on this species the genus 

 Potamogale has a wide geographic range, and hence might be expected 

 to have developed local phases. It is not the purpose of these remarks 

 to discredit such a reasonable probability but merely to show that the 

 evidence presented for the two forms above cited is far from adequate. 

 Unfortunately, little material is available for direct comparison with 

 that from the Upper Congo region, but the latter emphatically shows the 

 trivial nature of the distinctions offered by their describers for the recog- 

 nition of allmani and argens. Reference has already been made (p. 

 5) to the stained condition of the underparts due to treatment of the 

 skins before they were made up. Apropos of this, and in response to my 

 inquiries, the collectors have informed me that "all living or freshly 

 killed specimens they saw had pure white, lustrous fur on the under 

 side, if not soiled by the reddish clay of these regions"; and they add 

 that "some of their own skins from the same places, when unpacked, 

 were yellowish, due to a difference in the method of preservation." 

 They also state that they "noticed that in many old, flat skins or por- 

 tions of them from the same localities, which they saw in the possession 

 of Europeans and natives, the originally white area was always yellowish 

 or brown." It is also well known that in museum specimens the white 

 underside of mammals long stored are apt to turn yellowish from fatty 

 matter retained in the skin, or from other causes, and therefore are un- 

 satisfactory as standards of comparison with freshly collected material. 



