SULA CORYI. 



69 



cue head and upper tail coverts become nearly orange. Outer portion of wing feathers, hoary. Bill, pur 

 phsh blue, more decidedly purple at base. Feet and gula sac, bluish, with the latter purple at base. ' Iris- 

 brown. Feet, crimson lake. These are the colors in life, but the gula sac dries yellowish, and the other- 

 parts become paler. Se.xes, similar in all stages. 



BauwN Pji.\se. Slaty brown tinged with creamy or yellowish, especially on head and neck, excepting 

 rump, upper and under tail coverts, and tail, which are white, and many specimens have the lower back a,t 

 so white. Wings, naked parts, and iris, as in the adult. 



0(XASiONAL Plumage. Similar to Adult on head, neck and below, but the upper portions are mottled 

 irregularly with slaty brown, and the outer portion of the tail is brownish. This is an unusual plumage. 



First Plumage. Sooty brown throughout, darkest on wings and tail, with tlie feathers hoary outwlird- 

 ly on the former, lightest below, and some of the feathers above are margined with yellow. Feet, very pale 

 yellow. 



Fig. 20. 



/0y/''^'/y^^y^-^M^^^^^^ 





Head of Cory's Gannet, Sula coryi, young in first feathers, taken on Little Cayman, May 2d, 1SS8. 



Nestlings. Pure white with the down very thick and long. The wines and tail feathers appear lon«' 

 before the others, tlien follow the scapularies, then the feathers of the back, then those of the body, while 

 the head and neck are covered last, and the bird has assumed the first plumage above described. 



DIMENSIONS. 

 Wing, 14.25 to 15.00; tail, 9.00 to 9..50; bill, culman, 3.15 to 3.-i3; depth at base, 1.00 to 1.19; tarsus, 

 1.20 to 1.40. 



OBSERVATIONS. 

 The fact that any species of gannet should exhibit two phases of plumage seems to be quite new to sci- 

 ence, yet I am forced to this conclusion by my careful observations of this species of gannet made on Little 

 Cayman in April 1S88. Here was a gannetry containing something like 10,0130 birds, and as they were ex- 

 ceedingly tame I had a most excellent opportunity of examining them. The mixed plumage of which I liave 

 spoken is peculiar, and the Common Gannet appears to have a similar phase of dress, which is, in both spe- 

 cies, worn for life, as are doubtless the brown and white phases in the present species. The only positively 

 known habitat of tliis species is the island of Little Cayman and probably Cayman Brae also. It is extreme- 

 ly probable, however, that this species occasionally finds its way to our soutliern coast 



DESCRIPTION OF NESTS AND EGGS. 



Nests, placed on trees or busiies, composed of sticks loosely arranged like those of herons, Hat on top, 

 and about twelve inches wide. 



Eggs, one in number, oval yellowish-green in color, covered with a white calcareous deposit. Dimen- 

 sions, 1..50 X 2.30 to 1.G5 x 2.30. 



