GEOGRAPHICAL DISTRIBUTION 341 
replaced in Circassia and Persia by another form; but southward 
of this imperfectly-drawn line our Nightingale may be found as 
a winter-visitant in Nubia and Abyssinia, as well as in Algeria, 
where it is reported as breeding, and it would seem to migrate 
thence so far as the Gold Coast. It is abundant in Spain and 
Portugal; but it is a stranger to Britanny, the western penin- 
sula of France, just as it is to the western peninsula of England.1 
One other example we may take, and this, though much less 
familiar, is equally instructive as exhibiting some of the as yet 
unexplained. peculiarities of Distribution. It shall be that of a 
bird belonging to a very different Order from the last, having 
habits entirely dissimilar, and presenting in most ways a great 
contrast. The Kentish PLover, Agialitis cantiana, a species first 
determined from specimens obtained on the coast of that English 
county whence it takes its specific name, has its breeding-place 
in Britain limited to the pebbly beach between Sandwich and 
Hastings, and in other parts of this kingdom only occurs as a 
chance straggler. Yet this species has a very wide range, breeding 
not only abundantly along the greater part of the coasts of the 
temperate and warmer portions of the Old World north of the 
Equator, but also occasionally in the interior, as at the base of the 
Caucasus and in the chotts of the North-African plains; while 
in its regular migration it wanders to the Malay Archipelago and 
South Africa, and is hardly to be specifically separated from a 
Plover which inhabits the coast of China, or from another which is 
found on the west coast of America from California southward, 
though the former has been described as distinct under the name of 
44. dealbata, and the latter under that of 4. nivosa. 
A remarkable case of restricted range is that of the Red 
Grouse, Lagopus scoticus, found—and in certain districts, as every 
one knows, numerously—in each of the three kingdoms, as well as 
in Wales. The details of its local distribution, as of that of all 
» other birds which breed in Great Britain, were carefully and con- 
cisely given by Mr. More (Ibis, 1865, pp. 1-27, 119-142, 425-458), 
and there is no need to dwell upon them here; but what is worthy 
of remark is that this particular species differs in no other essential 
character save coloration from the Willow-GrRouss, L. albus, which 
is an abundant bird throughout the whole of the northern parts 
of the Holarctic Region, from Norway to Kamchatka, and again 
from Alaska to Newfoundland. Its remains, as before stated 
(FossiL Birps), have been found in the south of France associated 
with those of the Snowy Owl and the Reindeer ; and, deferring for 
the present any hypothetical discussion, it is impossible to resist 
the inference that our own bird, though fully entitled to the rank of 
a “species,” is a local form of the widely-spread Willow-Grouse. 
1 Cf. Yarrell, British Birds, ed. 4, i. pp. 315-318. 
