126 ‘BANGS, The American Three-toed Woodpeckers. yea 
measurements are about the only means of distinguishing the 
males of the various forms of 4. pheniceus, we must rely upon 
them to determine this bird’s relationship. The’ measurements 
given? for A. Jongirostris —wing, 111; tail, 81; culmen, 27; 
depthfof bill, 10; tarsus, 28 —are sufficient to show that it is 
decidedly smaller with a longer and slenderer bill than the form 
described by Mr. Ridgway as A. f. sonoriensis. Five males of the 
latter from Culiacan, Sinaloa, Mexico, average: wing, 127 ; tail, 
g1; culmen, 22.5; tarsus, 31; and the smallest of the series 
measures, wing, 126; tail, 88; culmen, 23; tarsus, 31. South 
of Culiacan in Mexico the birds are still larger and to the north 
somewhat smaller, especially in Arizona, whence-came the type 
of A. p. sonoriensis, but they never approach the dimensions 
given by Salvadori. After an examination of the considerable 
series of birds now available from various points in Arizona and 
western Mexico, from the Arizona border south to San Blas, 
Tepic, it is evident that the name A. /ongirostris cannot be 
properly applied to the bird named 4. /. sonortensis by Mr. 
Ridgway. It is very probable that the type of A. dongirostris was 
attributed to western Mexico through some error in labeling. 
A REVIEW OF THE THREE-TOED WOODPECKERS 
OF NORTH AMERICA. 
BY OUTRAM BANGS. 
In North America, as is well known, two very different kinds 
of Three-toed Woodpeckers are found. These are the Picordes 
arcticus series (black-backed Three-toed Woodpeckers), and the 
Picoides americanus series (black-and-white-backed Three-toed 
Woodpeckers). Both are boreal species and over a very large 
extent of country a representative of each occur together. Both 
species may be subdivided into geographical races — P. arcticus 
into two, P. americanus into four. Of these six races, one of 
P. arcticus, inhabiting the Cascade Mountains, and one of 7. 
americanus, found in Labrador, Nave not before been recognized. 
There is furthermore a mistake in the synonymy of P. americanus 
which makes it necessary to give the form of northern New Eng- 
