THE BIRDS OF CLIPPERTON AND COCOS ISLANDS 



511 



GYGIS CANDIDA (Gmelin). 



Sterna Candida Gmelin, Syst. Nat., i, p. 607, 1788. 



Gygis Candida Saunders, Cat. Birds Brit. Mus., xxv, p. 149, 1896. 



Range. — Intertropical. In the eastern Pacific : Cocos and Clip- 

 perton Islands. Not heretofore recorded from American waters. 



Adult Male and Fetnale. — Plumage above and below pure white. 

 A narrow black ring around the eye. Shafts of wing quills, the greater 

 wing coverts and rectrices dark brown. Bill (in life) blue at base, 

 black distally. Feet with tarsus and toes blue, claws black, webs white. 



The collection contains 6 adult specimens, i male and 5 female, 

 from Cocos ; also the wing of a specimen from Clipperton. We did 

 not secure a specimen on Clipperton, although one evening we saw 

 an individual alight on one of the houses on the island. The occu- 

 pants of the house said that the birds frequently come there, but were 

 never common. Mr. F. I. Shepherd, chemist on the island, gave us 

 the wing of one of the birds that had been killed on the island. Meas- 

 urements of the six adult specimens are as follows : 



MEASUREMENTS, IN MILLIMETERS, OF Gygis Candida. 



Abundant in July at Cocos Island, where it was nesting in the tops 

 of tall trees a short distance inland, in company with Micranous dia- 

 mesus. We did not secure any eggs. The nests, built of twigs, some- 

 what resembled those of a crow. Many nests were frequently found 

 in one tree. The birds were difficult to obtairt from the water, for 

 in flying back and forth from their nests they nearly always remained 

 at the same elevation as the nests. 



HETERACTITIS INCANUS (Gmelin). 



Scohpax incana Gmelin, Syst. Nat., Ed. x. Vol. I, p. 658, 1788. 

 Heteractitis incanus Ridgway, Proc. U. S. Nat. Mus., xix, p. 632, 1896 



(Galapagos). — Rothschild and Hartert, Novitates Zoologicae, vi, p. 



188, 1899 (Galapagos). 



Range. — Eastern Pacific Ocean. Occurs at Guadalupe Island, 



