BIRDS OF NORTH AND MIDDLE AMERICA 215 



h. Size smaller, wing, c? not over 200 mm., 9 not over 225 mm. 

 (Cozumel Island) __B. magnirostris gracilis, juv. (p. 334) 

 hh. Size larger; wing, (^ over 215 mm., 9 230 mm. or over. 

 i. Upperparts dark; fuscous to olive-brown. 

 j. Ground color of underparts definitely tinged with buffy 

 (eastern and southern Mexico). 



B. magnirostris griseocauda, juv. (p. 339) 

 jj. Ground color of underparts whitisli, only slightly tinged 

 with buffy. 

 k. Pectoral streaks darker — fuscous (Colima to northern 



Oaxaca) B. magnirostris xantusi, juv. (p. 341) 



kk. Pectoral streaks paler — dark sepia (Oaxaca to north- 

 ern Chiapas) _-B. magnirostris petersi, juv. (p. 343) 

 n. Upper]iarts pale; drab to pale hair brown (Yucatdn to 

 northern Brit. Honduras). 



B. magnirostris conspectus, juv. (p. 342) 

 gg. Underparts not whitish streaked with reddish brown, but 

 abdomen and flanks barred with reddish brown. 

 h. Size smaller; vdng, cf not over 200 mm., 9 not over 225 mm. 

 (Cozumel Island) _.B. magnirostris gracilis, ad. (p. 344) 

 hh. Size larger; wing, c? over 215 mm., 9 230 mm. or over. 

 i. Upperparts brownish with very little grayish wash. 



j. Ground color of underparts distinctly tinged with buffy. 

 k. Crown and nape dark brownish (eastern and southern 

 Mexico) __B. magnirostris griseocauda, ad. (p. 338) 

 kk. Crown and nape blackish (Bay Islands, Honduras). 



B. magnirostris sinus-honduri, ad. (p. 347) 

 jj. Ground color of underparts whitish, only slightlj' tinged 

 with buffy. 

 k. Abdominal bars darker — Saccardo's umber (Colima 

 to northern Oaxaca). 



B. magnirostris xantusi, ad. (p. 341) 

 kk. Abdominal bars paler — Sayal brown (Oaxaca to 

 northern Chiapas). 



B. mag^nirostris petersi, ad. (p. 343) 

 a. Upperparts decidedly grayish brown (Yucatdn to northern 

 Brit. Honduras). 



B. magnirostris conspectus, ad. (p. 342) 

 //. Pale interspaces of rectrices with some rufous. 

 g. Pale interspaces of rectrices entirely rufous. 

 h. Abdomen barred with rufous. 

 i. Breast feathers with two incomplete white bars, producing 

 a spotted appearance (Pearl Islands). 



B. magnirostris alius, ad. (p. 350) 

 a. Breast feathers without anj' white bars (Pacific slope Costa 

 Rica to eastern Panama). 



B. magnirostris petulans, ad. (p. 348) 

 hh. Abdomen streaked with rufous. 



B. naagnirostris petulans, juv. (p. 348)"* 



"> Juvenal plumage of Buteo m. alius not known, but probably differs from that 

 of petulans chiefly in having the rufous interspaces on the rectrices paler. 



