NO. 1847. THE LADDER-BACKED WOODPECKERS— OBERHOLSER. 153 



flanks and crissum with bars of the same; lining of wing white, with 

 spots of black. 



Measurements. — Male:* Wing, 102-109 (average, 105.1) mm.; tail, 

 57.5-68 (61.9); exposed culmen, 21.5-24.5 (23.1); tarsus, 18-19.5 

 (18.9); middle toe, 12.5-14 (13.2). 



Female :2 Wing, 97-104.5 (100.6); tail, 56-63.5 (59.7); exposed 

 culmen, 17.5-22 (19.6); tarsus, 16-18.5 (17.1); middle toe, 11.5-13 

 (12.3). 



Type-locality. — Tucson, Arizona. 



Geographical distnhution. — Southwestern United States and north- 

 western. "Mexico : w^est to Guaymas, southwestern Sonora; Cocopah 

 Major Mountains and Gardners Laguna on Salton River, north- 

 eastern Lower California; Vallecito, Riverside, and Hesperia, south- 

 western Cahfornia; north to Victorville, southwestern California; 

 eastern base of Charleston Mountains, and Vegas Wash, southern 

 Nevada ; Santa Clara, southwestern Utah ; Beaverdam, northwestern 

 Arizona; Camp Verde and Holbrook, central Arizona; Glen wood, 

 southwestern New Mexico; Abiquiu, middle northern New Mexico; 

 Corona, central New Mexico; and Santa Rosa, central eastern New 

 Mexico; east to Montoya, Fort Sumner, and the Guadalupe Moun- 

 tains, eastern New ^lexico; Fort Da\4s and Tornillo Creek, central 

 western Texas ; south to the Chisos Mountains, central western Texas ; 

 Rio Sestin, northwestern Dm'ango; Nacori, south central Sonora; 

 Guaymas, southwestern Sonora; and Colony (Colorado River), 

 northeastern Lower California. 



From Dryohates scalaris hairdi this form differs in its much less 

 deeply smoky under surface, sometimes \\dth lateral black spots 

 (always streaks in D. s. hairdi) ; lighter upper parts — tlie black bars 

 narrower, the white bars broader, the pileum vnth more white; 

 wider white -bars on wings; larger white spots on remiges; and much 

 larger white spots on outer webs of primary coverts. It may be 

 distinguished from Dryohates scalaris scalai'is by its much greater size ; 

 paler lower surface, which has usually streaks on breast and sides, 

 insteacl of only spots, and these markings of black heavier; broader 

 black bars on upper parts; larger white spots and broader white 

 bars on remiges ; wider postocular and malar stripes, the latter ex- 

 tending quite to the base of the bill ; and more extensive white spots 

 on the outer webs of the primary coverts. 



The birds from northwestern Durango are somewhat smaller and 

 darker than those from Arizona^ and verge thus toward Dryohates 

 scalaris centrophilus,^ but seem to be nearer the present form. Ex- 

 amples from Nacori and Bacadehuachy, central Sonora, are small 

 and dark, and incline thus toward Dryohates scalaris agnus, though 



1 Ten specimens, from Arizona and southern Utah. 



« Twenty-two speoimens, from Arizona, Sonora/ and northeastern Lower Califomiaj 



3 See p. 157. 



