200 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



ff. Outer web of lateral rectrix with proximal half unbarred. 



g. Smaller (wing averaging 86.8 in. male, 84 in female; tail 45.8 in male, 

 44 in female) ; black bars on distal portion of lateral rectrices broader. 



(British Honduras.) Dryobates scalaris leucoptilurus (p. 249). 



gg. Larger (wing 92, tail 48.5, in male); black bars on distal porljion of 



lateral rectrices narrower. (State of Michoacan, southwestern 



Mexico.) Dryobates scalaris azelus (p. 251). 



dd. Larger (wing averaging more than 100 in male, more than 96 in female). 



e. Outer web of lateral rectrix with proximal half unbarred; black bars on 



back, etc., not wider than white ones, or else (D. «. lucasanus, D. s. ere- 



mkus) the posterior under parts less heavily barred. 



/. Smaller (wing averaging 100.8 in male, 96.8 in female). (Southern 



Sonora.) Dryobates scalaris agnus (p. 252). 



ff. Larger (wing averaging 102 or more in male, more than 99 in female). 

 g. Smaller (wing averaging 102 in male, 99.2 in female; tail 63 in male, 

 63.8 in female; exposed culmen 24.5 in male, 20.5 in female); under 

 parts paler. (Southern Lower California.) 



Dryobates scalaris lucasanus (p. 252). 

 gg. Laj^er (wing averaging 106.6 in male, 101.4 in female; tail 68 in male, 

 66.9 in female; exposed culmen 26.9 in male, 23.9 in female); under 

 parts darker. (Northwestern Lower Califorinia.) 



Dryobates scalaris eremicus (p. 253). 

 ee. Outer web of lateral rectrix usually distinctly barred on proximal halt. 

 /. Posterior under parts less heavily barred; black bars on back, etc., not 

 wider than white ones. 

 g. Black bars on back, etc., not narrower than white ones. 

 h. Larger (wing averaging 104 in male, 101.5 in female; tail 60.8 in 

 male, 62.4 in female; exposed culmen 22.7 in male, 19.8 in female); 

 under parts paler. (Extreme western Texas to southern Cali- 

 fornia and extreme north«n Lower California, north to southern 

 Nevada and Utah, and south to northern Durango.) 



Dryobates scalaris cactophilus (p. 254). 

 M. Smaller (wing averaging 102.1 in male, 99.6 in female; tail 57.7 in 

 male, 56.9 in female; exposed culmen 20.9 in male, 17.5 in 

 female); under parts darker. (States of Jalisco, southern 

 Dimmgo, Zacatecas, and northwestern Michoacan, western 

 Mexico.) 



Dryobates scalaris centrophilns (p. 256). 

 gg. Black bars on back, etc., narrower than white ones. (Size of D. s. 

 centTophilus.) (Texas, Nuevo Leon, northern and middle Tamau- 

 lipas, and north to southeastern Colorado.) 



Dryobates scalaris symplectns (p. 257). 



ff. Posterior under parts more heavily barred; black bars on back, etc., 



wider than white ones. (Size of D. s. cactophilus.) Southeastern part 



of Mexican plateau in San Luis Potosf, Guanajuato, Puebla, Hidalgo, 



etc.) Dryobates scalaris bairdi (p. 258). 



65. Scapulars imiform brown, 

 c. Median portion of back and rump broadly barred or transversely spotted with ' 

 white. (Southeastern Mexico, in States of Vera Cruz, Puebla, Mexico, and 



MoreloB.) Dryobates strieklandi (p. 259). 



cc. Whole back and rump uniform brown. {Dryobates arizonse.) 



