Fes., 1912. MamMAts oF ILLINOIS AND WISCONSIN— Cory. 339 
form and apparently show marked intergradation. When the time 
comes that a sufficiently large series from various localities can be 
gathered together for comparison, it may be found that all of our 
large Skunks belonging to this genus are merely geographical races of 
one or possibly two species, four of which intergrade within our limits. 
For the laity it is perhaps as well to consider all the Skunks belonging 
to the genus Mephitis, which are found within our limits, to be either 
hudsonica or avia, but many specimens are not typical of either and 
possess characters more or less approaching mephitis or putida, as 
shown by the following brief descriptions of a series of Skunks in the 
Field Museum collection from Green Bay, Wisconsin. The measure- 
ments are in millimeters. 
No. 11708, 9 — Palate with distinct median spine, but zygomata widely expanded; 
white stripes extending on sides of tail about % its length; end of tail blunt and 
entirely black. 
Total length, 625; tail vertebre, 195; hind foot, 63.5. 
No. 11706, 9 — Palate with distinct median spine and skull similar to preceding; 
tail mostly black, but ending with a long white pencil. 
Total length, 660; tail vertebra, 220; hind foot, 68. 
No. 11704, o&' — Palate with indication of median spine; skull narrower than 
hudsonica and zygomata approaching mephitis; white stripes extending on sides 
of tail to about 3% its length; end of tail blunt and entirely black. 
Total length, 615; tail vertebra, 185; hind foot, 64.5. 
No. 11703, 6! — Palate evenly rounded, without spine; white stripes extending on 
tail 14 its length; end of tail black. 
Total length, 560; tail vertebre, 174; hind foot, 56.5. 
No. 11702, o&' — Palate without median spine; skull narrower and zygomata 
approaching mephitis more than avia; white stripes extending on tail; whole end 
of tail broadly white. 
Total length, 600; tail vertebre, 215; hind foot, 61. 
No. 11701, o — Skull badly broken; zygomata badly broken and absent; white 
stripes extending on sides of tail; end of tail blunt and entirely black. 
Total length, 655; tail vertebre, 230; hind foot, 74. 
No. 11707, 9 — Skull badly broken; palate without median spine; white stripes 
extending on sides of tail about % its length; tail mixed with long white hairs; 
end of tail black. 
Total length, 675; tail vertebra, 220; hind foot, 67.5. 
No. 11720, 9 — Skull large but badly broken, palate without median spine; white 
stripes extending but slightly on base of tail; end of tail black, with a few long 
white hairs extending from the tip. 
Total length, 685; tail vertebra, 220; hind foot, 70. 
No. 11721, 9 — Palate evenly rounded, without median spine; skull approaching 
mephitis; white stripes short, not reaching the rump; rump entirely black; tail 
black, with the whole end white for about 4 inches. 
Total length, 635; tail vertebra, 215; hind foot, 69. 
No. 18395, oc? — Galena, Illinois, Skull resembling avia, but white stripes of body 
extending on sides of tail nearly to the end; end of tail black; a small white spot 
on the lower part of the throat. 
Total length, 623; tail vertebra, 258; hind foot, 75. 
