HARTMAN — BROWN MUTATION IN OPOSSUM 
147 
all authors, the black phase predominating (cf. Allen 1901, and Mearns, 
1907). I have had about 20 specimens of this subspecies from San 
Benito, Cameron County; all of these were black.^ For D. virginiana, 
however, Allen (1901) fails to mention the black phase, and one would 
gather from his monograph that none but the gray occurs in this species. 
Elliot (1901), however, had two blacks among his twelve Virginia 
opossums from Florida. In August, 1919, I saw a black of this species 
lying by the roadside near Oxford, Iowa. At Austin, Texas, the black 
phase of virginiana is found frequently. For example among the last 
200 females of my records 15 are designated as “black^^; but as the 
records were made for other than taxonomic purposes it is likely that 
several blacks escaped description in my notes. The percentage of 
blacks in central Texas is probably near ten per cent. From these 
facts it would appear that the black phase has received inadequate 
attention at the hands of mammalogists, although from the standpoint 
of genetics the blacks are of special significance. 
The chief interest attaching to the black phase pertains to the inde- 
pendence of pigmentation of overhair and underfur. For it should be 
recalled that in grays and in blacks the underfur is alike, that is, it is 
white except for the black tip. The long, coarse overhair, however, 
is either white or black for its entire length on any given animal.^ An 
animal is gray or black according to the color of the overhair. Some 
blacks have a few or even many white overhairs among the black, 
chiefly posteriorly; but there seems to be no intergrading series between 
the gray and the black phases. Dark gray specimens, for which Bangs 
(1898) attempted to set up a new subspecies {D. virginiana pigra), 
are often met with in this locality. No analysis of our dark grays has 
as yet been made, but they, too, are in a different class from the blacks. 
Corresponding to these two normal phases of the opossum are the 
brown animals now to be described in which brown pigment has re- 
placed black. Two specimens, skins Nos. 235543 and 235535, of the 
United States National Museum, Biological Survey Collection, were 
caught somewhere near Houstonia, Cooper County, Missouri, Decem- 
ber, 1920, and were sent in by Dr. Chas. A. McNeill of Sedalia, Missouri, 
who states that according to information he has been able to gather 
2 It is possible that blacks only were selected for shipment and that these 
therefore do not represent random catches. 
’ The writer has among his notes a reference to a Virginia opossum having 
individual overhairs partly white and partly black. Such specimens must be 
very rare. 
