Classification of the Mongooses. 519 
almost to the angle of the cheek, the two molars being 
reduced so as to fit into the short dental area behind it. 
The lower carnassial (m1) is correspondingly large and the 
last molar quite small. The first premolar, always small and 
sometimes absent, is evidently a practically functionless 
tooth, but, when absent, its former position is marked by the 
persistence of the space between the canine and the second 
premolar. 
Helogale (type parvula) may be regarded as a dwarfed 
Mungos, in which the diastema has closed up by the shortening 
of the jaw. 
Atilax (type paludinosus) is related to Mungos, but has 
very specialized feet, as is testified by the suppression of the 
interdigital webs. The slightly more forward position of the 
upper carnassial and the larger size of the two molars suggest 
its being an offshoot from the AZungos + Helogale stem before 
the retrogression of the carnassial was completed, ‘The 
exceptional massiveness of the teeth and jaws are probably 
an adaptation for crushing the shells of the river-crabs on 
which it feeds to a great extent. 
Ichneumia (type albicuuda) has teeth * of a more gene- 
ralized type than Mungos, and in that particular comes nearer 
the hypothetical primitive form, but it differs therefrom at 
least in the hairiness of the hind feet and more digitigrade 
gait. The depth of the upper lip below the rhinariuw is also 
uo doubt a specialized feature. 
Bdeogale (type crassicauda) shows many dental resem- 
blances to Ichneumia, as ‘Thomas pointed out t. Specializa- 
tion of the feet, however, is carried a stage further than in 
that genus, as is shown by the shortening of the four main 
digits and the suppression of the hallux and pollex. 
* Of the teeth of Ichneumia albicauda Thomas wrote in 1882 :— 
“Teeth more rounded than in the members of the typical subgenus 
[Mungos]. Last molars above and below proportionately much larger 
.... the lower one with a well-marked extra cusp between the usual 
ones, so that there are five cusps in all.” To this it may be added that 
the first’ molar of the upper jaw is nearly as large as the carnassial ( pi‘), 
though lower crowned, and occupies the position of the carnassial in 
Mungos, being inserted well in front of the superjacent base of the zygo- 
matic arch, 
+ He wrote, “Of all the mongooses H. albicauda [Ichnewmia] seems 
to be most nearly allied to true Bdeogale, strongly resembling the species 
of that genus in... . the proportionally large size of the last molar, and, 
most of all, in the presence of the median middle external cusp to the 
last molar, a character in which Bdeogale differs from all other mongooses 
except the present species and those of the very distinct genus 
Crossarchus.’ 
34* 
