. Key to North American birds. Containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary, inclusive of Greenland and lower California, with which are incorporated General ornithology: an outline of the structure and classification of birds; and Field ornithology, a manual of collecting, preparing, and preserving birds. Birds; Birds; 1887. Fig. 53. — Lobate foot of a coot; Fig. 53 his. — Ltibate foot of pliala- rope, Loblpes hyperboreus; nat. size. Claws and Spurs. —With rare anomalous ex
. Key to North American birds. Containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary, inclusive of Greenland and lower California, with which are incorporated General ornithology: an outline of the structure and classification of birds; and Field ornithology, a manual of collecting, preparing, and preserving birds. Birds; Birds; 1887. Fig. 53. — Lobate foot of a coot; Fig. 53 his. — Ltibate foot of pliala- rope, Loblpes hyperboreus; nat. size. Claws and Spurs. —With rare anomalous exceptions, as in the case of an imperfect hind toe, every digit terminates in a complete claw. The general shape is remarkably constant in the class; variations being rather in degree than in kind. A cat's claw is about the usual shape: it is compressed, arched, acute. The great talons of a bird of prey are only an en- largement of the typical shape ; and, in fact, they are scarcely longer, more curved, or more acute than those of a delicate canary bird ; they are simply stouter. The claws of scansorial birds are very acute and much curved, as well as quite large. The under surface of the claw is generally excavated, so that the transverse section, as well as the lengthwise outline below, is concave, and the under surface is bounded on either side by a sharp edge. One of these edges, particularly the inner edge of the middle claw, is expanded or dilated in a great many birds ; in some it becomes a perfect comh, having a regular- series of teeth. This pyectination (Lat. pecten, a comb), as it is called, only occurs on the inner edge of the middle claw. It is beautifully showTi by all the true herons (Ai'deid/s) ; by the whip-poor-wills and night-hawks (Cap)rimulgidce, fig. 41); by the frigate pelican (Tachypetes); and imperfectly by the barn owl (Ahico flammeus). It is supposed to be used for freeing parts of the plumage that cannot be reached by the biU from parasites; but
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbirds, bookyear1887
