ters adopting a number of generic groups, while others
consider that very few meet the needs of the case. In retaining the
old genus _Canis_ in the wide sense, that is to say, inclusive of the
foxes, Professor Max Weber is followed. The best cranial character by
which the different members of the family may be distinguished is that
in dogs, wolves and jackals the post-orbital process of the frontal
bone is regularly smooth and convex above, with its extremity bent
downwards, whereas in foxes the process is hollowed above, with its
outer margin (particularly of the anterior border) somewhat raised.
This modification coincides in the main with the division of the group
into two parallel series, the Thooids or Lupine forms and Alopecoids
or Vulpine forms, characterized by the presence of frontal air-sinuses
in the former, which not only affects the external form but to a still
greater degree the shape of the anterior part of the cranial cavity,
and the absence of such sinuses in the latter. The pupil of the eye
when contracted is round in most members of the first group, and
vertically elliptical in the others, but more observations are
required before this character can be absolutely relied upon. The form
and length of the tail is often used for the purposes of
classification, but its characters do not coincide with those of the
cranium, as many of the South American _Canidae_ have the long bushy
tails of foxes and the skulls of wolves.

[Illustration: FIG. 5.--The African Hunting-Dog (_Lycaon pictus_).]

The most aberrant representative of the thooid series is the African
hunting-dog (_Lycaon pictus_, fig. 5), which differs from the other
members of this series by the teeth being rather more massive and
rounded, the skull shorter and broader, and the presence of but four
toes on each limb, as in _Hyena_. The hunting-dog, from south and east
Africa, is very distinct externally from all other _Canidae_; being
nearly as large as a mastiff, with large, broadly ovate erect ears and
a singular colouring, often consisting of unsymmetrical large spots of
white, yellow and black. It presents some curious superficial
resemblances to _Hyena crocuta_, perhaps a case of mimetic analogy,
and hunts its prey in large packs. Several local races, one of which
comes from Somaliland, differing in size and colour, are recognized
(see HUNTING-DOG). Nearly related to the hun