4. Coccygus minor.
5. Coccygus erythrophthalmus. 27028.
The preceding diagnoses will serve to distinguish the three groups sufficiently for our present purposes; the bill being strongest in the Picinæ and best fitted for cutting into trees by its more perfect wedge-shape, with strengthening ridges, as well as by the lateral bevelling of both mandibles, which are nearly equal in thickness at the base, and with their outlines nearly straight. The lateral ridge is prominent, extending to the edge or end of the bill, and overhangs the nostrils, which are narrow and hidden. The Centureæ and the Colapteæ have the upper mandible more curved (the commissure likewise), the lower mandible smaller and weaker, the bill with little or no lateral bevelling. The nostrils are broadly oval and exposed. In the former, however, there is a distinct lateral ridge visible for a short distance from the base of the bill; while in the other there is no ridge at all, and the mandible is greatly curved.
In all the species of North American Woodpeckers, there is more or less red on the head in the male, and frequently in the female. The eggs of all are lustrous polished white, without any markings, and laid in hollow trees, upon a bed of chips, no material being carried in for the construction of the nest.
Section PICEÆ.
With the common characters, as already given, there are several well-marked generic groups in this section of Woodpeckers which may be arranged for the United States species as follows:—