1906.] Allen, Mammals from Western Mexico. 231 



whatever it may be, extends nearly to the base of the pelage; on the 

 nape and posteriori y, the hairs are basally light (varying in different 

 specimens from soiled buffy gray to strong yellowish buff), with a 

 broad subapical band of black, and a still broader terminal band of 

 pale yellow to ochraceous, according to the specimen. In the series 

 of very light specimens the light basal portion of the pelage extends 

 nearly to the surface, the subapical dark band is much narrower and 

 less dark, and is more heavily veiled by the long light tips of the hairs, 

 which are distinctly whitish. In such examples the top of the head 

 is of an extremely pale shade of buff, in rare cases almost yellowish 

 white ; on the nape and shoulders the yellowish shade is somewhat 

 stronger, and the subapical dark band is narrower and browner 

 brown rather than black. 



The facial markings vary correspondingly in the tone of .the dark 

 areas from brown to black, and the superciliary stripes and other 

 light markings vary more or less in width and extent, and from 

 dingy white to clear white. In all the phases the inner surface of 

 the ears is either clear white or yellowish white; the outer surface 

 conforms to the color of the adjoining parts. 



The tail varies with the general coloration, being blackish through- 

 out in the 'black phase, ' yellowish or buffy in the extreme light phase, 

 and variously intermediate in other phases, according to the general 

 coloration, but always, except in the darkest specimens, gradually 

 darkening about the middle to the end, the apical third being much 

 darker than the basal third. In many specimens the tail is obsoletely 

 ringed, the dark bands being only slightly darker than the adjoining 

 intervals; they are generally most apparent on the middle third of 

 the tail, and so slightly developed as to be noticeable only on close 

 inspection. 



That the above-described color variations are purely individual 

 is evident from the fact that both sexes are about equally represented 

 in all the phases, that the half -grown young share them equally with 

 the adults, and that all occur at one and the same locality, and that 

 all have been taken at practically the same dates, in the December, 

 January, February, and April series of from 15 to 30 specimens each. 



Cranial Variation due to Sex and Age. In view of the inconstancy 

 of the coloration in the present series of Coatis from Escuinapa, due 

 wholly to individual variation, it is surprising to find so little variation 

 in the cranial characters of the same specimens that is not obviously 

 due to differences of sex and age. In regard to sexual differences, 

 the female is much smaller than the male. In old skulls, with worn 



