Note 7 — INTRODUCTION.

As remarked by Sundevall, exceptions to the diagnostic pertinence of these two characters of hind claw and wing-coverts taken together are scarcely found. For, in those non-passerine birds, as Raptores and some Herodiones, in which the claw is enlarged, the wing-coverts are otherwise disposed; and similarly when, as in many Pici and elsewhere, the coverts are of a passerine character, the feet are highly diverse.