rBOCEEDIXGS OF THE NATIONAL MUSEUM. 525 



GEOSPIZA FRATERCULA, Ridgway. 

 (Plate LVII, tig. 16.) 



Geosjriza forfis (uee Gould), Salvin, Truus. Zool. .Soc, IX, Pt. ix, 1876, p. 481 

 (part: Abingtlou Island).— IJiixiway, Proc. U. S. Nat. Mus., XII, 1880, p. 107 

 (Abiugdou Island). 



ireospizafratercnla, Ridgway, Proc. U. S. Nat. Mus., XYII, No. 1007, Nov. 15, 1894, 

 p. 363 (Abingdon Island, (Galapagos Archipelago; collection U. >S. Nat. Mus.). 



f^pecific characters. — Similar to G.fortis, Gould, of Cliarles Island, but 

 smaller, the bill uarrower aud with culmeu more couvex. Adult males : 

 Wing, 2.50-2.05; tail, 1.00-1.05; culraen, 0.05-0.07; basal M'idth of man- 

 dible 0.30-0.40; depth of bill at base, 0.43-0.40; tarsus, 0.78-0.80. 



Range. — Galapagos Arcbipelago : Abingdon Ishiud {Hiib&\, Albatross). 



Adidt w«7f.— Type, No. 110110, T'.S.K.M.; Abingdon Island, Galapa- 

 gos, April 10, 1888; C. IT. Townsend. Entirely deep black, very faintly 

 tinged with olive posteriorly, especially on the ruiii]), all tlie feathers 

 abruptly clear slate-gray beneath the surface; bill wholly deep black; 

 legs aud feet brownish black. Length (skin), 4.05; wing, 2.08; tail, 

 1.72; culmen, 0.03; gouys, 0.34; basal width of mandible, 0.35; basal 

 depth of bill, 0.42; tarsus, 0,80; middle toe, 0.53. 



Immature ( ?) male. — Xo. 110109, U.S.N.M. ; same locality, etc. Head, 

 ueck, and chest uniform black; rest of upper parts black, the feathers 

 margined with olive, most broadly so on back, scapulars, rump, and 

 upi^er tail-coverts; breast and sides duller black, the feathers margined 

 with light olive-grayish ; flanks grayish brown ; middle of belly and anal 

 region dull whitish, the feathers dusky beneath the surface; under tail- 

 coverts light buff, each feather with a dusky Avedge-shaped central 

 space; bill and feet as in the fnlly adult male. Length (skin), 4.75; 

 wing, 2.58; tail, 1.70; culmen, 0.()5; gonys, 0.34; basal width of man- 

 dible, 0.30; basal depth of bill, 0.45; tarsus, 0.77; middle toe, 0.54. 



Younf/ maJe. — Xo. 116113, U.S.X.M.; same locality, etc. Above 

 brownish black, the feathers margined with olive, especially oji back, 

 scapulars, rump, etc.; middle and greater wing-coverts broadly mar- 

 gined with dark bufty or clay color; chin and throat grayish dusky 

 obsoletely streaked with i)ale buffy grayish ; chest and upper breast 

 with broad streaks of dusky and narrower ones of pale grayish buffy; 

 rest of under i^arts plain grayish buffy white medially, olive grayish 

 laterally, tinged with brownish buffy and obsoletely streaked with 

 darker; under tail-coverts very pale buff or buffy white; bill dark 

 brown, with the terminal and lower halves of the mandible pale yel- 

 lowish; legs and feet brownish dusky. 



Some other young males in first plumage differ from the one de- 

 scribed in being darker (nearly uniform blackish brown) above, and in 

 having the whole chin and throat " solid" dusky. 



Five adult males in the United States National Museum collection 

 from Abingdon Island agree in the above characters, by which they 



