BIRDS OF NORTH AND MIDDLE AMERICA. 495 



M. Bill narrower (not more than 8.89 deep at base), with basal portion of 

 culmen not elevated nor arched. 

 /. Bill broader (basal width of mandible equal to length of gonys), with 

 distinctly curved or convex culmen and more obtuse tip. 

 g. Larger (tarsus 18.54 or more, averaging 19.81; wing averaging 63.50, 

 tail averaging 39.12, culmen averaging 13.21). (Charles, Chat- 

 ham, Hood, Albemarle, Narborough, James, Barrington, Duncan, 

 Indefatigable, Gardner near Charles, and Jervis islands. ) 



Geospiza fuligiuosa (p. 504) 



gg. Smaller (tarsus less than 18.54, averaging 18.03; wing averaging 



58.17, tail averaging 36.32, culmen averaging 12.70). (Bindloe 



and Abingdon islands. ) Geospiza minor (p. 506 ) 



ff. Bill narrower (basal width of mandible less than length of gonys), 

 with nearly straight culmen and acute tip. (Tower Island.) 



Geospiza acutiroBtris (p. 506) 

 aa. Bill relatively long and slender, the transverse width of the mandible at base 

 (measured across interramal space) decidedly less than length of gonys. 

 {Cactomu.) 

 b. Culmen not more than 16.26. (Wenman and Culpepper islands.) 



Geospiza septentrionalis (p. 510) 

 66. Culmen not less than 17.78. 



c. Depth of bill at base not more than 9.40 (averaging 8.89). (James Island.) 



Geospiza scandens (p. 509) 

 CO. Depth of bill at base not less than 9.91. 



d. Culmen not less than 18.54; depth of bill not more than 10.41 (or else cul- 

 men not less than 21.59). 

 e. Smaller (wing averaging 70.36, culmen averaging 19.81, tarsus averaging 

 21.59). (Charles Island, and Gardner Island near Charles.) 



Geospiza intermedia (p. 511) 



ee. Larger (wing averaging 72.39 or more, culmen averaging 20.83 or more, 



tarsus averaging 22.35 or more). 



/. Smaller with more slender bill (wing averaging 72.39, culmen averaging 



20.83, depth of bill at base averaging 10.16, tarsus averaging 22.35). 



(Indefatigable, Albemarle, Duncan, Jervis, Chatham, and Barrington 



islands. ) j Geospiza fatigata (p. 511 ) 



ff. Larger with thicker bill (wing averaging 73.41, culmen averaging 21.84, 

 depth of bill at base averaging 10.92, tarsus averaging 23.11) . (Ab- 

 ingdon and Bindloe islands; James Island?) 



Geospiza abiugdoni (p. 513) 



dd. Culmen 17.78; depth of bill 11.43. (Charles Island; Indefatigable 



Island?) Geospiza breviroetria (p. 514) 



GEOSPIZA MAGNIROSTRIS Gould. 

 GREAT-BILLED GROUND FINCH. 



Largest species of the genus, with largest and thickest bill; wing, 

 90.17-95.00 in males, 82.55-87.63 in females; culmen, 26.42-26.92 in 

 males; depth of bill at base, 23.37-23.88 (23.62) in males. 



Adult male. — Uniform black, the primaries and rec trices more 

 dusky; under tail-coverts broadly margined with white; bill and feet 

 black; length (skins), about 152.40; wing, 91.00-95.00, averaging 



