PHALACROCORACIDiE — THE CORMORANTS — PHALACROCORAX. 151 



Similar to tlie above, but tufts of the head wanting, and the Ijare skin of the lores, gular pouch, 



etc., deep yellow instead of orange, and the l)lue of the mouth and eyelids absent. Youwj, first 



plumaye : Head and neck grayish brown, lighter next to the gular sac, darker on the crown and 



nape ; baok, scapulars, and 



wings, dull brownish gray, 



the feathers bordered with , , , 



dusky brown ; rump dusky 



brown ; primaries and tail 



dull grayish black ; lower 



parts light fawn-color, dark- 

 er on the sides, anal-re- 

 gion, and crissum. Bill dull 



brownish yellow, nearly 



black on the culmen ; gular 



sac deep chrome yellow ; 



iris greenish gray ; legs and 



feet deep black. Young, in 



ivinter: Similar to the above, 



but throat, juguluui, and 



breast paler, sometimes quite 



white. 



Total length, about 29 

 to 33 inches ; extent, 45 to 

 55; wing, 11.20-14.00 ; tail, 

 5.60-8.50 ; culmen, 1.90- 

 2.55 ; tarsus, 2.05-2.90 ; 

 longest toe, 3.05-3.75. (A ^' '^^^''^> nuptial dress. 



marked increase of size to the northward.) 



A very careful examination and comparison of more than fifty examples of these birds very 

 clearly proves the identity of the three supposed species respectively called by authors P dilo- 

 phus, P. flondanus, and P. cincinnatus, the latter representing a very marked geographical modi- 

 fication of color ; the 

 so-called _/?on'f?a?t«s, on 

 the other hand, repre- 

 senting merely a slight 

 modification of size. 

 The examination in 

 question shows the 

 geographical variation 

 in this species to be 

 of two kinds, viz. : (1) 

 A more or less marked 

 increase of size to the 

 northward, and (2) a 

 gradual change from 

 uniform glossy black 

 nuptial crests, in east- 

 ern birds, to crests 

 entirely pure white, or 

 with merely a slight 

 admixture of black, 



P. dilophus cincinnatus, nuptial dress. 



bare space on the head, and gular sac, rich orange. Feet and claws black." "P. flnridanus :"—" Adult 

 male, in spring : Upper mandible black, along the basal margins briglit blue ; lower bright blue, curiously 

 spotted with white. Iris light green, margins of eyelids light blue, spotted with white. Bare space on 

 the head and gular sac rich oiange. Feet and claws grayish black." 



