Classification of the Mongooses. 521 
more arched zygomata, and the inflation of the anterior 
chamber of the bulla, coupled with the large perforation 
close to the tympanic bone. 
Asin Ichneumia, Mungos, and others, the foramen rotundum 
opens into the alisphenoid canal, probably a primitive feature. 
The teeth of the upper jaw are somewhat more sectorial than 
in Ichneumia, as is shown more particularly by the narrower 
palatal portions of the two molars. 
Aricela (type fasciata), with some points of resemblance to 
Mungos in its semiplantigrade pentadactyle feet, has never- 
theless a more generalized dentition. The highly developed 
anal sack and absence of groove on the snout are specialized 
features. In one character connected with the skull it differs 
from all the genera hitherto considered (? Rhynchogale)— 
namely, in the opening of the foramen rotundum direct into 
the temporal fossa and not into the alisphenoid canal, the 
anterior aperture of the latter being situated alongside that 
orifice and separated therefrom by a narrow bony partition, 
Crossarchus (type obscurus), resembling Ariela in the 
particular last mentioned, has a less specialized anal sack and 
a more specialized snout. 
Suricata (type swricatta) has always been admitted to hold 
an isolated position amongst the mongooses, and the now 
ascertained differences in the structure of its ear enhance the 
isolation. 
Generically it may be distinguished from the rest of the 
family by a complex of associated characters, like the general 
form of the skull, the elongated snout, undivided upper lip, 
tetradactyle feet, and naked tarso-metatarsus. The shape of 
the skull, with its bowed zygomata and complete and stout 
postorbital bars, recalls in a measure that of Cynictis ; but 
the great difference in the form of the bulle, apart from 
other features, precludes the idea of near affinity between 
the two genera. The long snout and undivided upper lip, 
resembling those features in Crossarchus, are likely enough 
to be purely adaptive resemblances ; but in the skull there 
is one significant similarity, namely, the situation of thie 
foramen rotundum alongside the anterior orifice of the ali- 
sphenoid canal and close to the sphenoidal fissure—a character 
restricted to Ariela, Crossarchus, ? Rhynchogale, aud Suricata, 
so far, at all events, as mongooses are concerned. I think it 
is a tenable hypothesis that Suricata is a highly specialized 
offshoot of the Ariela+ Crossarchus stock of this family. In 
that case, the ear of Suricata may be regarded as secondarily 
simplified. Nevertheless, a comparison between this ear and 
that of the Mascarene Galidictine genera forcibly suggests 
