596 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.40. 



races is somewhat interesting, and is worthy of mention here. The 

 Newfoundland bird, Dryobates villosus terraenovae, is most closely allied 

 to Dryobates villosus leucotlwrectis / from New Mexico and Arizona, 

 and very different from the races that occupy the intervening 2,000 

 miles; while both Dryobates villosus harrisi and Dryobates villosus 

 picoideus, from Alaska and British Columbia, approach much nearer, in 

 color at least, to Dryobates villosus hylobatus 2 and Dryobates villosus 

 enissomenus , 3 from central Mexico, than to the races that are geograph- 

 ically adjacent. The northern Bahama Islands are occupied by two 

 forms, which have become differentiated, in the color of the lores, from 

 all the other subspecies, probably by isolation. Furthermore, there is 

 almost a regular increase of size toward the north, from the smallest 

 race, Dryobates villosus extimus, of Panama, to the two largest, Dry- 

 obates villosus monticola, of Montana and British Columbia, and Dryo- 

 bates villosus septentrionalis of Mackenzie and Alaska. 



The adult female hairy woodpecker differs from the male only in 

 somewhat smaller size and in the absence of the red occipital band. 

 The juvenals of both sexes closely resemble the adults, except that 

 nearly the whole top of the head is red. 



In the measurements given under the various forms, none but 

 perfectly typical specimens have been used, except in a few cases 

 where such exclusion was rendered inadvisable by the smallness of 

 the series available; for to include intermediates in measurement 

 averages manifestly obscures the differences that really exist. The 

 length of the tail is less reliable than other dimensions, as it is in all 

 woodpeckers, since, on account of the unusual amount of wear to 

 which the feathers are subject, it varies greatly. All measurements 

 are in millimeters. In the lists of specimens examined, each locality 

 is to be regarded as a breeding station unless specific statement is 

 made to the contrary. 



The following key may serve for an aid in distinguishing the 

 various forms, in addition to setting forth their salient characters 

 more clearly than do the descriptions. 



KEY TO THE SUBSPECIES OP DRYOBATES VILLOSUS. 



a. Lores entirely white. 



b. Inner webs of outer tail-feathers without black spots . Dryobates villosus maynardi. 

 ¥. Inner webs of two or three outer pairs of tail-feathers with subterminal black 



spots Dryobates villosus piger. 



a! . Lores partly black. 



b. Upper wing-coverts with many and conspicuous white spots, 

 c. Size smaller; spots on wing-coverts smaller; lower parts less purely white. 



Dryobates villosus audubonii. 

 ef . Size larger; spots on wing-coverts larger; lower parts usually pure white. 

 d. Smaller, wing of male usually less than 128 mm. (average, 120.9). 



Dryobates villosus villosus. 



i See p. 608. s See p. 617. 3 See p. 614. 



