492 NORTH AMERICAN BIRDS. 



Subfamily PICIN^. 



The diagnosis on the preceding page will serve to distinguish this group 

 from its allies, without the necessity of going into greater detail. It in- 

 cludes by far the largest percentage of the Picidm, and in the great variations 

 of form has been variously subdivided by authors into sections. Professor 

 Sundevall, in his able monograph/ establishes the following four series, refer- 

 ring all to the single genus Picus : — 



I. Angusticolles. Neck slender, elongated. Nostrils concealed by- 

 bristles. Tail-feathers black or brownish, immaculate. 



II. Securirostres. Neck not slender, and shorter. Nostrils concealed 

 by bristles. Bill stout, cuneate, with the nasal ridges widely distant 

 from each other. 



III. Iiigonirostres. Neck not slender. Nostrils covered, nasal ridges 

 of bill placed near the culmen (or at least nearer it than the lower 

 edge of the upper mandible), for the most part obsolete anteriorly. 



IV. Nudinares. Nostrils open, uncovered by bristly hairs. Neck and 

 bill various. 



Of these series, the first and second correspond with Picece, as given below, 

 while Centurem and Colaptece both belong to Ligonirostres. The Nudinares 

 are not represented in North America, and by only one group, Celeus, in any 

 portion of the continent. 



In the following account of the Picincc, we shall not pretend to discuss 

 the relationship of the North American species to the Picinm in general, 

 referring to Sundevall's work, and the monographs of Malherbe and Cassin, 

 for information on the subject. For our present purposes they may be con- 

 veniently, even if artificially, arranged in the following sections : — 



Piceae. Bill variable in length ; the outlines above and below nearly 

 straight ; the ends truncated ; a prominent ridge on the side of the 

 mandible springing from the middle of the base, or a little below, and 

 running out either on the commissure, or extending parallel to and a 

 little above it, to the end, sometimes obliterated or confluent with the 

 lateral bevel of the bill. Nostrils considerably overhung by the lateral 

 ridge, more or less linear, and concealed by thick bushy tufts of feathers 

 at the base of the bill. Outer posterior toe generally longer than the 

 anterior. 



Centureae. Bill rather long ; the outlines, that of the culmen espe- 

 cially, decidedly curved. The lateral ridge much nearest the culmen, 

 and, though quite distinct at the base, disappearing before coming to 

 the lower edge of the mandible ; not overhanging the nostrils, which 

 are broadly oval, rounded anteriorly, and not concealed by the bristly 

 feathers at the base. Outer pair of toes nearly equal ; the anterior 

 rather longer. 

 Colapteae. Bill rather long, much depressed, and the upper outline 



^ Conspectits avium pidnarum. Stockholm, 1866. 



