MAMMALS OF MINNESOTA. 91 
: thus brought about in the weasel causes the great reduction of 
the last molar and the apparent revolution of the axis through 
90 degrees, so that it stands at right angles to the remainder of 
the series. It is this condition of the orbits and zygoma and 
the abbreviation of the facial region which finds its extreme in 
the weasels which produces, in part at least, the great exten- 
sion of the palate in that group; and the converse condition 
in Mephitis produces the effect of a deep emargination of the 
palate extending frequently as far as the molars. In most of 
the other Mustelide the palatal bridge extends more than half 
way to the pterygoids. 
The form of the teeth, as well as their position, differs from 
that of the types of the family. The upper incisors are chisel- 
shaped and bent backward near the end, while those of the 
lower jaw are straight and squarely truncate apically, opposing 
the surface thus formed to the oblique edge of the upper teeth. * 
The lower premolars are small and conical, while the third 
upper one isthe sectorial. Ithas, however, avery considerable 
development of the salient anterior lobe found even in Putorius 
but so highly developed in the badgers that the tooth is as 
much a grinder as asectorial. The upper molar is quadrate, 
but wider than long. The lower jaw as a whole differs very 
little from that of the Musteline. The foramina incisiva are 
narrow. The posterior nares are separated by a bony septum 
almost to the posterior edge of the palate. The pterygoids 
are hooked and of moderate size. The zygomatic arch is not 
compressed laterally, nor as strongly curved upward as in 
the Musteline. The glenoid fossa is of considerable size and is 
well arched behind, yet looks more downward than in the 
weasels, although never locked. The auditory bulla lies close 
to the post-glenoid prominence, and the meatus opens just 
posterior to the zygomatic process of the temporal, in contrast to 
that of the Musteline. The bulle are very little inflated, in this 
respect differing greatly from the badgers. The mastoid pro- 
cesses are produced and directed forward. 
Generic characters of Mephitis. 
Teeth, 34; formulas: i. $:3. ¢, [:4, pm. #3, m. 3:4. Frontal region 
tumid, dorsal outline of skullirregular. Palate not extending 
beyond the molar series. Condyle of mandible projecting later- 
ally, coronoid process with both margins convex, angle slightly 
flaring outward. Soles quite narrow. Tail very long and 
bushy. Color black with white dorsal markings. 
It is now accepted that there are but two valid species of 
