198 BRITISH BIRDS. 
never a Raptorial tooth as in the Shrikes. The bastard primary is always 
present—a character which separates the Thrushes from the Wagtails and 
the Swallows, and also from all the British Finches. In the British 
examples of the Turdine it is sometimes very small, but never so minute 
as in the Starlings and in the Waxwings. In all of them, however, it is 
much narrower than the second primary, and not half as long, a character 
which will serve to distinguish the British Thrushes from the Crows. The 
young in first plumage differ from the adults in having the upper and 
underparts more or less spotted; but they moult into adult plumage in 
their first autumn before they migrate. Adults moult only in the autumn, 
usually attaining their nuptial dress by casting the ends of the feathers, 
which deepen in colour at the same time. The Turdine are nearly cosmo- 
politan, and probably number more than seven hundred species, of which 
about one hundred are European. Nearly one third of these inhabit our 
islands, or visit them more or less regularly. The British Turdine belong 
to ten genera. Many of these are so closely related, that they can only 
be recognized by courtesy or as a matter of convenience. There are no 
structural characters on which to form a key to the genera. The chief 
character which has been relied upon is the pattern of the colours, which 
will be described in each genus. 
Genus GEOCICHLA. 
The genus Geocichla is supposed to have been established by Kuhl 
about the year 1825; and Geocichla interpres is considered the type; 
but the original publication of this genus has not yet been found, and is 
probably in some obscure Dutch periodical. It contains a number of 
Thrushes distinguished as Ground-Thrushes, and supposed to be the least 
changed descendants of the ancestors of the true Thrushes and Ouzels. They 
are characterized by having the basal portion of the outside web of all the 
secondaries and of many of the primaries white, occasionally tinted with 
buff, but abruptly defined from the brown of the rest of the quills, and 
forming a peculiar pattern on the under surface of the wing. The axil- 
laries are particoloured, the basal half being white, and the terminal half 
black, slate-grey, or brown. Most of the under wing-coverts are similarly 
particoloured ; but the relative position of the colours is reversed, the white 
portion being on the terminal half. These characters serve to distinguish 
them from all other allied genera. 
The genus Geocichla contains about forty species, principally confined 
to the Oriental and Aithiopian Regions. Three species of the genus 
