A T 0.3.] ALLEN ON THE GENUS BASSARIS. 337 



Mexico. The next darkest specimen is from Orizaba, Mexico. The lower 

 surface is sometimes nearly pure white, but is usually strongly tinged 

 with pale yellow, varying in some specimens to pale brownish-yellow, 

 especially on the chin and throat. The relative amount of black and 

 white on the tail is also variable. In the lighter specimens, the greater 

 portions of the lower surface of the tail is pure white ; in others, the black 

 rings are only broken below by a narrow band of white. In the Oregon 

 specimen, they are almost continuous below (the last two apical ones 

 wholly so), though much narrower than above. The rings usually 

 increase in width from the base of the tail apically, especially in case of 

 the black ones. 



The extremes of variation in color are in specimens No. 11849, from 

 Camp Grant, Arizona (E. Palmer), and No. 12849, from Oregon (A. H. 

 Wood). The Arizona specimen is pale brownish-gray above, varied 

 with blackish, principally along the median line, caused by the black 

 tips of the long hairs. Below it is pale yellowish-white. The tail is 

 mostly white below, but above is crossed by alternate rings of black and 

 white of nearly equal breadth. The Oregon specimen has the prevail- 

 ing tint of the dorsal region intense black, quite obscuring the brownish- 

 gray ground-color. Below, it is strongly brownish-yellow, deepest on 

 the throat and chin. The tail is mostly black above, the white being 

 mostly half-rings confined to the lower surface. These two specimens 

 accord with the peculiar phases of geographical color- variation com- 

 monly characterizing the mammals and birds of the two regions in 

 question. Should the Oregon specimen here described prove to indicate 

 the average condition of the species along the Pacific coast to the north- 

 ward, as seems probable, the form there prevailing may require to be 

 varietally distinguished under the name raptor ', Baird, this name doubt- 

 less referring to the Pacific coast form, as already explained. Five 

 specimens from near the southern border of Texas agree in being rather 

 darker than the Arizona specimen, and present only a moderate range 

 of color- variation. A specimen from Orizaba (No. 8567, $ , Botteri) is 

 rather darker, the lower surface more strongly yellow, and the white on 

 the tail is slightly tinged with yellow. 



In a young specimen about one-fourth grown, and still retaining the 

 milk dentition, the pelage is soft, long, and woolly 5 the color above pale 

 yellowish -brown varied with darker brown, but with no Hack; below 

 grayish-white, faintly tinged with yellow anteriorly. The tail has seven 

 white rings, and the light spots below and behind the eyes are nearly 

 pure white. 



In old female skulls, in which the teeth show a considerable degree of 

 attrition, there is no trace of a crest. Probably in old males this will 

 be found to be present, but the only male specimens before me are only 

 of middle age and do not show it. The most notable variation in the 

 skulls of B. astuta is the unusually wide separation of the pterygoid 

 bones, and the consequent unusual breadth of the posterior nares in 



