LIFE HISTOEIES OF NORTH AMERICAN PETRELS AND PELICANS. 131 



that the specimen described was Oceanodroma hornbyi, notwithstanding minor 

 discrepancies in the amount of white pictured on the face and throat. The 

 figure was drawn from a poorly mounted bird, which doubtless accounts for 

 slight distortions of the color areas. Both of the specimens have been seen by 

 Dr. Frank M. Chapman during visits to Santiago. 



During the Brewster-Sanford South American expedition of the American 

 Museum of Natural History, Mr. RoUo H. Beck collected 56 specimens of 

 Oceanodroma hornbyi in the offshore waters of the Peruvian coast and proved 

 that the species is a common bird In this region. Mr. Beck's specimens were 

 aU taken during June, 1913, between the approximate latitudes of Ancon (11° 47' 

 S.) and Cerro Azul (13° 4' S.) in waters from 15 to about 2(X) miles from the 

 shore. He 'first noted the species in the vicinity of Hormigas de Afuera Islets, 

 38 sea miles west of Callao, on June 4. On June 6, when about 200 miles off- 

 shore, he obtained the first specimens, along with numerous examples of Oceano- 

 droma markhami and other petrels. Thereafter he saw 0. hornbyi frequently, 

 chiefly beyond 25 miles from shore, often feeding and coming to his bait in 

 groups of a score or so. His notes of June 25, on which date he collected 30 

 miles off Cerro Azul, contain the observation that in early morning, while the 

 sun was still low, the white breasts of Hornby's petrels shone like silver as the 

 birds darted back and forth among other species. After June 27 he changed 

 his field of operations to the islands and Inshore waters of the Pisco Bay 

 region, and thenceforth saw the species no more. 



All of Beck's specimens, the majority of which still remain In the Brewster- 

 Sanford collection, are birds which had resting sex organs. Most of the Indi- 

 viduals were completing or had recently completed the molt and renewal of the 

 flight feathers. 



In the same month of a later year, June, 1916, Dr. Frank M. Chapman also 

 observed Hornby's petrel along the Peruvian coast. He has kindly supplied 

 me with the following extract from his notes of June 23, 1916 : 



" Leave Pisco at 7.15, make the Boqueron In the face of a stiff breeze. At 

 8 a. m. we were about ten miles offshore, and the ocean, swarmed with petrels; 

 a large, black Puffinus, and a smaller one, in countless numbers were actlvte, 

 except one fiock of several hundred resting on the water. Many gannets were 

 diving from a height of from fifty to sixty feet. A few yellow-nosed albatrosses 

 were seen — splendid, sweeping creatures. There were several white-rumped 

 petrels and dozens of O. hornbyi; the latter the most erratic flier I have ever 

 seen — like a bat, swift, and nighthawk in one. They were skimming here, 

 flitting there, then suddenly swung off with the wind a hundred yards or more 

 so quickly one nearly lost sight of them." 



To these field notes Doctor Chapman has added the following comment, re- 

 lating to the apparent absence of the species during the perlor of the year 

 which doubtless includes Its breeding season: 



" December 4-7, 1918, while en route from Callao to Mollendo, I sailed over 

 this same area, but although on the lookout for them I did not see a single 

 Hornby's petrel." 



With regard to the breeding locality of O. hornbyi, we have only the in- 

 formation published by PhUippi. This author's second paper relating to the 

 species (Anales del Museo Naclonal de Chile, vol. 15, sect. 1, pp. 90-92, pi. 42, 

 1902) is in part a reprint In Spanish of the German description cited above, 

 with the addition of a colored plate. He states somewhat more fully that the 

 mounted specimen in the Santiago Museum was obtained on the tableland 

 east of Taltal, at a considerable altitude. In company with a dead chick of the 

 same species, and that he therefore believes this region to be the petrel's 



