1902.] Allen, Opossums of the Genus Didelphis. 273 



below yellowish white, washed with grayish brown, due to the brown 

 tipping of the longer hairs; limbs and feet wholly black, the former 

 with a few scattered white hairs; head white with the dark markings 

 very broad ; the median stripe begins somewhat in front of the eyes 

 and extends as a narrow band to the nape; the lateral stripe begins 

 a little behind the eye, extends forward to the nose, and abruptly 

 widens on the upper side, opposite the middle of the eye, so as to 

 occupy nearly the whole of the side of the nose in front of the eye, 

 where the two lateral stripes nearly meet, being separated by a light 

 median space only about half as wide as the dark eye-stripe; the 

 lower edge of the black eye-stripe forms a straight line running a 

 few millimeters below the eye; immediately surrounding the eye and 

 in front of it the dark stripe is intense black, but more anteriorly 

 passes into brown-black, and immediately behind the eye quite dis- 

 appears, leaving the space between the eye and ear dusky grayish 

 white, through a slight dusky tipping to the hairs. The light area on 

 the head begins on the nose as a narrow whitish band, dividing some 

 distance in front of the eyes and passing, as a V-shaped mark on 

 either side of the pointed median black band, back to the ears, spread- 

 ing out laterally behind the eyes till it joins the white cheek-band, 

 with, as already said, the tips of the hairs between the eyes and ears 

 slightly obscured with dusky. The usual broad white cheek-band 

 occupies the whole area below the eyes, from the nose to the side of 

 the neck, which is superficially obscured with dusky, and often suffused 

 basally with yellowish brown or gamboge. Ears hairy at the base, 

 usually wholly light or flesh-color, but of a deeper, browner (not dusky) 

 tint basally than apically; some specimens show dusky blotches 

 basally. Tail black basally for about one third to one half the length 

 of the naked portion, the rest light or flesh-color, but the relative 

 extent of light and dark portions very variable. 



Black phase. Wholly without the long white overhairs, but other- 

 wise similar to the gray phase. In the black phase the ears seem to 

 show less tendency to dusky blotching at the base than in the gray 

 phase. 



The color of the ventral surface varies greatly in different individuals, 

 in both phases. In some specimens the chin, throat, and breast are 

 dull grayish or buffy white, while the rest of the ventral surface is 

 superficially black, the whitish underfur showing only on parting the 

 pelage. In other specimens the whole ventral surface is whitish, just 

 as in the so-called albiventris phase of true paraguayensis . 



Young. Four very young specimens, in first pelage, from Cuenca, 

 Ecuador, are dull black above profusely lined with white, the future 

 white overhair; below thinly clothed with short hairs of a dull soiled 

 white. Eye-stripe merely an oval ring enclosing the eye, its future 

 extension, both anteriorly and posteriorly, outlined by a dusky tinge. 

 Ears wholly flesh-color, very hairy on both surfaces. 



[AllgttSt, IQ02.~\ 18 



