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besides the true Bears, only the genera Procyon, Nasua, Cercoleptes, 
and Ailurus. I must confess that I cannot concur with him in in- 
cluding the subfamily Mustelina among the feline family, and at the 
same time separating the Bears from them as a separate family ; for 
the course of my observations has convinced me that the Weasels are 
decidedly more closely allied to the Bears than to any other members 
of the order. Numerous genera have at various times been one after 
another abstracted from the Bear-tribe, and added to that of the 
Weasels, until at length only the four that I have mentioned have 
remained associated with the Bears. Some remarks in Mr. Water- 
house’s paper seem to imply considerable affinity between the Weasels 
and the Cats. He observes, ‘‘ The Cats appear to bear the same 
relation to the Mustelide as the Dogs to the Viverride.” This may 
be, but I should not consider that relation a very close one. He 
alludes particularly to the straightness of the lower jaw as a common 
character of the two groups: in the first place, I would remark, that 
this character is by no means constant among the Weasels; and 
secondly, that it is merely a circumstance of form, resulting from other 
adaptive modifications of the form of the entire cranium, such as the 
relative length of the jaws, and the development, both in size and 
number, of the molar teeth. As the posterior termination of the 
molar series is always on a rather lower level than the glenoid cavity, 
and as the line of the dental series inclines regularly upwards and 
forwards, it follows, that for the incisors of the lower jaw to close 
with those of the upper, the lower jaw must be curved in proportion 
as the jaws are lengthened. 
Among the characters which I have pointed out in the base of the 
cranium, it will be seen that the only tangible distinction between 
the Bears and the Weasels is the presence of the ali-sphenoid canal 
in the former, and its constant absence in the latter. Muchas I 
have insisted upon the importance of this character as assisting to 
distinguish groups, I do not consider it sufficient alone to entitle the 
groups which it separates to the rank of families ; neither am I pre- 
pared to admit the difference of the teeth sufficient for that purpose, 
these being, as I before observed, merely adaptive modifications. In 
the true Bears the number of true molars is on each side two above, 
and three, the full normal number, below. In the Weasels it is only 
one above and two below. In the subursine group, to which I must 
add the Bassaris astuta of North America, it is two above and two 
below; and among these it is only the Ailurus fulgens, an Indian 
species, which possesses the ali-sphenoid canal; while the other four 
genera, namely Procyon, Nasua, Cercoleptes, and Bassaris, all Ame- 
rican forms, agree among themselves in possessing the general cha- 
racters common to the Bears and the Weasels, and’ in having no 
ali-sphenoid canal, and two true molars on each side in each jaw. 
The Bassaris astuta has most usually been placed among the Viver- 
rine section, in which it also appears in the list published by Mr. 
Gray; but doubts have at various times been entertained as to that 
being its true station. Mr. Waterhouse remarks, in a note appended 
to the paper from which I have before quoted, ‘‘ From an examination 
