77 
outwards along the lower and posterior margin of the foramen ovale. 
This group is constantly marked by the entire absence of the ali- 
sphenoid canal. In the remaining characters this group presents no 
essential difference from the Bears ; the commencement of the canalis 
caroticus is usually near the middle of the inner side of the auditory 
bullz, and anteriorly the vessel does not again quite reach the outside 
of the cranium, simply showing itself at the point where it doubles, 
through the cartilage covering the foramen lacerum anterius. The 
characteristic form of the auditory bulla has been alluded to, and 
may be traced through the different modifications which it presents ; 
these mostly depend simply on the size of the species, it being much 
more swollen in the smaller ones, and in the small species of true 
Weasel much elongated: the mastoid and paroccipital processes also 
are developed in relation to the dimensions of the species, or even the 
age of the individual ; in the smallest species they have scarcely any 
projection, while in the larger ones they show the same essential 
structure as in the Bears, and different from that to be described in 
other groups. The peculiarities usually exhibited in this group by 
the lower jaw deserve some mention, even though not sufficiently 
constant to characterize the group, because some similar characters 
are seen in certain genera of the Viverrine section, which also show 
some approach to the Weasels in the characters of the base of the 
cranium, and therefore seem to be entitled in their own group to the 
place nearest the adjoining one. The characters in question are, 
that the coronoid process is rather more upright, and has less curva- 
ture than usual in the order, and the angular process is placed closer 
to the condyle, and is flattened beneath. ‘The straightness of the 
lower margin of the jaw, alluded to by Mr. Waterhouse in a short 
communication published a few years ago in the Proceedings of the 
Society, I will consider by and by. 
In the Viverrine group there is always a distinct indication of a 
true pterygoid fossa; the ridge by which it is bounded externally is, 
in the true Civets, cut off suddenly behind: in the Paradoxuri and 
allied genera it extends further, being blended with the walls of the 
ali-sphenoid canal, and in some species terminating laterally in a 
minute process. In the Herpestine genera, which are those most 
approaching to the Weasels, the true pterygoid bones are more ex- 
tended backwards (which is most usually the case in that group, and 
also in the Bears), and the outer margin of the fossa is very suddenly 
cut off, as in the true Civets. With very few exceptions, the ali- 
sphenoid canal is present in this group: in the second edition of the 
‘ Legons d’Anatomie Comparée,’ the Genets are spoken of as wanting 
it; it exists however in the skulls that I have seen; the only exce 
tions that I have as yet met with are in the skulls of the Rasse 
(Viverra malaccensis) and of the small species of Galictis, recently 
described by Mr. Gray. In all the other characters, however, these 
crania indicate clearly the natural affinities. Had these exceptions 
been of the opposite kind, that is, had the ali-sphenoid canal been 
present in some species of a group in which it is usually absent, they 
might have been serious obstacles to the use of this character; but 
