Vol. II, Pt. I] GIFFORD— BIRDS OF THE GALAPAGOS ISLANDS 39 



ing season. One specimen was in slightly worn plumage 

 dorsally, with pin- feathers still appearing in the breast; an- 

 other was in fresh plumage, apparently with no growing 

 feathers; the third, No. 1628, was in fresh plumage, with pin- 

 feathers in the white lower parts and the remains of a sheath 

 at the base of each distal primary. Now as these specimens 

 are, in all likelihood, in nuptial plumage, the presence of a 

 sheath at the base of a distal primary, in connection with the 

 freshness of all the primaries, would seem to indicate a pre- 

 nuptial moult of the flight-feathers as in the terns. Nothing 

 in the entire series contradicts this assumption, but, neverthe- 

 less, I do not feel that I have enough light on the subject to 

 assert positively that such is the case. 



Thirty-three adults with enlarged sexual organs, from an 

 islet off the northeast coast of James Island, were taken late 

 in July and early in August. All are in fresh or slightly 

 worn plumage (primaries included) and exhibit but little or 

 no feather-growth. In these as well as in all other adults 

 examined, some of the tertials and longer scapulars are worn, 

 and not in harmony with the rest of the plumage. This is 

 undoubtedly due to two causes ; first, that some of the feathers 

 are hold-overs, and second, that they are more subject to wear 

 than other parts of the plumage. 



Of three specimens from Cowley Island, August 13, two 

 are quite fresh and show no pin-feathers. The third is some- 

 what worn, and has pin-feathers appearing in the back and in 

 the white under parts. 



A female from Culpepper Island, September 25, 1906, is in 

 full fresh plumage, except for a much abraded long scapular 

 and somewhat ragged outer rectrices. No pin-feathers or 

 other indication of feather-growth are to be found. As this 

 species breeds on Culpepper in July, this specimen is probably 

 in postbreeding plumage. 



A female (No. 1721 C. A. S.) taken at sea on May 8 is 

 adult in every particular, save that the hood is mottled with 

 pure white feathers, and the naked parts in life were paler 

 than they are in the average adult. Numerous new dark 

 feathers are appearing on the head to replace the worn white 

 ones. A few pin-feathers are also to be found in the back 

 and breast. The primaries and rectrices are slightly worn 



