BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 53 



genus Oceanodroma rather than in Procellaria^ where in P. pelagica, 

 the type species, the tail is slightly rounded. 



OCEANITES GRACILIS GRACILIS (Elliot) 

 Thalassidrotna gracilis Elliot, Ibis, 1859, p. 391. (Chile.) 



On the evening of May 7, 1921, 15 kilometers west of Lobos de 

 Afuera Island, Peru, four graceful petrels, attracted by the lights, 

 were captured on board ship. On deck they were helpless and even 

 by aid of their wings were barely able to walk. When handled they 

 gave a low chirping call. All were males, in which the outermost 

 primaries had been molted recently, so that one or two of the outer 

 ones were still inclosed in sheaths. They agree in color and char- 

 acters with the type of this species preserved in the National Mu- 

 seum, save that the wing is shorter, due to the molting primaries. 

 In most of a series studied by Loomis ^^ the molt came from late 

 November to early January, though one June specimen had recently 

 shed the primaries. My skins vary in amount of white on the abdo- 

 men from a diffuse wash on the tips of the feathers in one to another 

 in which the white forms a solid well-defined patch. The wing in 

 the type specimen of the species measures 131.2 mm. Measurements 

 for two of my specimens are 118.3 mm. in each case, but these birds, 

 as stated above, have just completed a molt and may have the pri- 

 maries not quite fully grown. They seem, however, to be smaller 

 than the form described as Oceanites g. galapagoensis Lowe ^^ from 

 the Galapagos Islands. 



Mathews *° has noted that in six specimens of the graceful petrel 

 five had the tarsus booted, while the other showed indistinct signs of 

 scutellation. In the six birds that are before me the tarsus is booted 

 with faint scutes indicated for a short distance at either end. 



Order CICONIIFORMES 

 Family PHALACROCORACIDAE 



PHALACROCORAX VIGUA VIGUA (Vieillot) 



Rydrocorax vigua Vieillot, Nouv. Diet. Hist. Nat., vol. 8, 1817, p. 90. 

 (Paraguay.) 



The common cormorant, known universally as vigua from its 

 appellation in Guarani, was observed in many localities. The species 

 was fairly common on the Rio Paragua}'^, from Corrientes as far 

 as Asuncion and increased in abundance from that point to Puerto 

 Pinasco. Scattered individuals were observed at Las Palmas, Chaco, 



ssproc. California. Acad. Sci., ser. 4, vol. 2, pt. 2, Apr. 22, 1918, p. 181. 

 »«Bull. Brit. Orn. Club, vol. 41, June 8, 1921, p. 140. 

 « Birds of Australia, vol. 2. pt. 1, May 30, 1912, p. 9. 



