PICID.E—PICIN.E: WOODPECKERS. 



589 



and lateral ridges, aud nasal tufts hiding nostrils ; very broad and mucli depressed at base, with 

 lateral ridges very low d(nvn, in most of their length close to and parallel with commissure; 

 nostrils very near commissure ; gonys about as long as from nostrils to end of bill. Wings 

 very long and pointed; 1st quill spurious; 2d between 6th and 7tii in length. Crown with a 

 square yellow patch in $ ; sides of head striped, of body barred, with black and white ; under 

 parts otherwise wliite; quills but not coverts with white spots; tail-feathers unbarred, outer 

 white, central black. All the species of this genus are unfjuestionably modified derivatives of 

 one circumpolar stock; the American seem to have become completely differentiated from the 

 Asiatic and European, and furtiier divergence has perfectly separated arctieus from americanus ; 

 but dorsalis, alascensis, and americanus are still linked together. 



Analysis oj Species anil Subspecies. 



Back uniform black arctieus 



Back with entirely interrupted lengthwise white stripe innericanus 



Back with nearly or (juite uninterrupted lengthwise white stripe. Rocky Mts , U. S a. dorsalis 



Back intermediate between the two foregoing. Alaska a. alascensis 



P. arc'tieus. (Lat. arctieus, arctic. Fig. 403.) Black-backed Tiiimi - ioed Wodd- 



I'ECKEK. Entire upper parts glossy 



blue-black, with only a few white spots 

 ])aired on wing-fiuills. Below, white 

 from hill to tail; side.-;. Hanks, and 

 lining of wings barred with black. A i 

 slight or concealed white postocular 

 strii)e (often wanting) and a side-stripe 

 on head from across forehead to neck, 1 

 cut off by black from white of under 



parts. Four nii(l<Uo tail-feathers black, 



rest white, but the intermediate one ^^^ ^^ ' 



usually touched with black. $ with a 



square yellow patch on crown, wanting " '' ■*'>- 



in 9- I>'11 i'lid feet blackish-plumbe- j . 



ous; iris brown. Length 9.00-10.00; "-^ '. 



extent 15.00-17.00; wing 5.00-5.r)0; ' M 



tail 4.00; bill 1.25 or more. Xorthera > j 



N. Am., S. in winter through most of «' '^• 



New England and generally along the | 

 northern tier of U. S., casually to Con- 

 necticut, Pennsylvania, and Illinois, in 

 the mountains of the West to about 39° 

 in Nevada and California. Breeds all 



through its regular range, which in- ' ^V**?/ 



chides the Ailirondacks of New York. ; /it 



and is not S[)ecially marked in habits, ' ^'~' " 



I'ut mainly affects coniferous forests. ' 

 I'.ggs oftcne.st 4, in May and June, aver- \ 

 auiiii: (».!».■> X 0.72. 



I>. iiiiiei-iea'iius. (Of America.) L.\i)- ''^^ 



l>l".Ii-BACKEI> TllRKE-THEl) W(l()I>- Fio 403 — Arctic Three-toed Woodpecker. (From The Osprey.) 



I'ECKKU. Fpiier parts black, middle line white, more or less completely barred across with 

 black; general effect thus of a " ladder- back." All primaries and secondaries with paired 



