s.

2. Interdigital glands on all 2. Interdigital glands, when
the feet. present, only on fore feet.

3. Suborbital gland and pit 3. Suborbital gland and pit
usually present. never present.

4. No beard nor caprine 4. Male with a beard and
smell in male. caprine smell.

5. Horns with coarse transverse 5. Horns with fine transverse
wrinkles; yellowish striations, or bold knobs
or brown; sub-triangular in front; blackish; in male
in male, spreading outward more compressed or angular,
and forward with a sweeping backward
circular sweep, points with a scythe-like curve or
turned outward and forward spirally, points turned upward
and backward.

These features are distinctive as between most sheep and most goats, but
the Barbary wild sheep (_Ovis tragelaphus_) has no suborbital gland
or pit, a goat-like peculiarity which it shares with the Himalayan
bharal (_Ovis nahura_), in which the horns resemble closely
those of a goat from the eastern Caucasus called tur (_Capra
cylindricornis_), which for its part has the horns somewhat
sheep-like and a very small beard. This same bharal has the goat-like
habit of raising itself upon its hind legs before butting.

Both groups are a comparatively late development of the bovine stock, as
they do not certainly appear before the upper Pliocene of Europe and
Asia, and even at a later date their remains are not plentiful. Goats
appear to have been rather the earlier, but are entirely absent from
America.

The number of distinct species of sheep in our fauna is a matter of too
much uncertainty to be treated with any sort of authority at this time.
Most of us grew up in the belief that there was but one, the well-known
mountain sheep (_Ovis canadensis_), but seven new species and
sub-species have been produced from the systematic mill within recent
years, six of them since 1897. It is no part of the purpose of the
present paper to dwell upon much vexed questions of specific
distinctness, and it will only be pointed out here that the ultimate
validity of most of these supposed forms will depend chiefly upon the
exactness of the conception of species which will replace among
zoologists the vague ideas of the present time. Whatever the conclusion
may be, it seems probable that som