80 U. Ss. P. R R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
The preceding diagnosis will serve to distinguish the three groups sufficiently for our present 
purposes, the bill being stronger in the Picinae 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 over- 
hangs the nostrils, which are narrow and hidden. The MMelanerpinae and the Colaptinae 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 Melanerpinae, however, there is a distinct lateral ridge visible for a short distance from 
the base of the bili; while in the other there is no ridge at all, and the mandible is greatly 
curved, 
Section Piceae. 
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: 
A. Posterior outer toe longer than the anterior outer one. 
a. Lateral ridge starting above the middle of the base of the bill and extending to the tip. 
1. Camprpnitus.—Lateral ridge above the middle of the lateral profile of the bill 
when opposite the end of the nostrils, which are ovate, and rounded anteriorly. 
Bili much depressed, very Jong, gonys very long. Posterior outer toe consider- 
ably longer than the anterior. Primaries long, attenuated towards the tip. 
Spurious quill nearly half the second. 
2. Picus.—Lateral ridge in the middle of the lateral profile opposite the end of 
the nostrils, which are ovate and sharp pointed anteriorly. Bill moderate, 
nearly as broad as high. Outer hind toe moderately longer than the outer fore 
toe. Primaries broad to the tip and rounded. Spurious primary not one-third 
the second quill. 
3. Prcorprs.—Lateral ridge below the middle of the profile, opposite the end of 
the ovate acute nostrils, which it greatly overhangs. Bill greatly depressed. 
Inner hind toe wanting, leaving only three toes. Tufts of nasal bristles very 
full and long. 
b. Lateral ridge starting below the middle of the base of the bili, and running as a 
distinct ridge into the edge of the commissure at about its middle; the terminal haif 
of the mandible rounded on the sides, although the truncate tip is distinctly bevelled 
laterally. 
4. Spuyraprcus.—Nostrils considerably overhung by the lateral ridge, very small, 
linear. Gonys as long as the culmen, from the nostrils. Tips of tail feathers 
elongated and linear, not cuneate. Wings very long; exposed portion of 
spurious primary about one-fourth that of second quill. 
B. Posterior outer toe considerably shorter than the anterior outer one. 
5. Hytatomus.—Bill depressed. Lateral ridge above the middle of the lateral 
profile near the base. Nostrils elliptical, wide, and rounded anteriorly. Tail 
as in Picus. Color, black. 
The arrangement in the preceding diagnosis is perhaps not perfectly natural, although suffi- 
ciently so for our present purpose. Thus, Hylatomus, in having the lateral ridge extending to 
