148 
JOURNAL OF MAMMALOGY 
from animal dealers brown opossums are occasionally taken by hunters 
in Cooper County. The third skin examined is No. 19083 of the 
United States National Museum, received from Warsaw, Illinois, 
in 1890. The first is of the ‘^all brown’’ variety, corresponding to the 
black phase; that is, all of the overhairs are brown except about a 
dozen white ones near the tail. It is darker than the other two, possibly 
approaching chocolate. The underfur is brown-tipped and brown 
pigment is seen in the skin of the snout and the scales on the proximal 
40 mm. of the tail. The ears seem to be black. The other two speci- 
mens differ from the first in having the overhair white; in other words 
they correspond to the normal grays. All the specimens are large 
and have the extremely short tails characteristic of D. virginiana. 
To summarize, then, four varieties of D. virginiana seem clearly 
differentiated: 
1. The gray phase, with underfur black-tipped, overhair all white. 
2. The black phase, with underfur also black-tipped, overhair alto- 
gether or for the most part black. 
3 and 4. Like 1 and 2, with brown pigment replacing the black. 
For an account of the occurrence of the brown mutation among 
mammals the reader is referred to Castle’s book “Genetics and Eu- 
genics” (1920) and to the several articles listed below. Recently 
Miller (1921) in this journal published a description of a brown mole, 
an insectivore; and with the present record the mutation is extended 
to the Marsupialia. This raises the question whether or not there is a 
very general distribution of the same factors involved in the develop- 
ment of coat color within the class Mammalia. 
Addendum. — Since sending the preceding article to the editor of 
the Journal the writer has been fortunate enough to secure from Doctor 
McNeill three additional specimens of the cinnamon opossum. They 
reached Austin, Texas, alive and in excellent condition from Sedalia, 
Missouri, where Doctor McNeill purchased them. Nothing else is 
known concerning their history. Of these three one enormous male 
and one two-year old female have white overhair; the third specimen 
is a yearling female without any white overhair whatever, that is, it 
is solid cinnamon. The feet and the base of the tail are brown. The 
ears are dark except for the unpigmented tip often seen in virginiana 
and marsupialis; but the pigmentation is light as compared with the 
black ears of the gray phase and tends toward brown, especially in the 
last mentioned individual. In this the ears are the lightest, and dis- 
tinctly and unmistakably brown. 
