FAMILY HYDROBATIDAE 45 



This form breeds on islands off the coast of Peru, where it is 

 reported on Isla Pescadores and Isla San Gallan. Murphy (Oceanic 

 Birds S. Amer., 1936, p. 731) records it as ranging south to the 

 latitude of northern Chile, and his supposition that these birds may 

 come northward as far as Panama is now verified. A male in the 

 British Museum (Natural History) was taken by the St. George 

 Expedition "near Balboa" on August 22, 1924. Two others of this 

 sex in the American Museum of Natural History were collected by 

 Robert Cushman Murphy, one during the Askoy Expedition, 4 miles 

 west of Punta Caracoles, Darien, February 26, 1941, and another 

 south of Punta Dirgado, Darien, September 11, 1937. 



Another, a male (now in the American Museum of Natural His- 

 tory), was taken by William Beebe, March 28, 1938, at Banco Han- 

 nibal, west of Isla Coiba. Dr. Beebe informed me that the bird came 

 to lights used in the night-collecting of marine animals. (See Beebe, 

 Book of Bays, 1942, pp. 280, 297.) 



OCEANITES GRACILIS (Elliot): Graceful Storm Petrel; Golondrina de 



Mar Chica 



Thalassidroma gracilis Elliot, Ibis, vol. 1, no. 4, Oct. 1859, p. 391. (Coast of 

 Chile.) 



A small petrel, with upper tail coverts and abdomen white. 



Description. — Length about 180 mm. Sooty black; upper tail 

 coverts and abdomen white. 



Reported as a casual visitor to the Gulf of Panama, according to 

 a sight record by Robert Cushman Murphy, cited by Eisenmann 

 (Trans. Linn. Soc. New York, vol. 7, 1955, p. 11). 



The typical race, O. g. gracilis, known from the west coast of 

 South America from Punta Santa Elena, Ecuador to Valparaiso, 

 Chile, with breeding grounds at present unknown, has the wing 117 

 to 132 mm., females being larger than males. Another form, 

 Oceanites gracilis galapagoensis Lowe, recorded only near the 

 Galapagos Islands, with nesting grounds also unknown, is larger, 

 with the wing 130 to 146 mm. 



It is the nominate form that may be expected north to Panamanian 

 waters. 



HALOCYPTENA MICROSOMA Coues: Least Petrel; Golondrina de Mar 



Menuda 



Figure 8 



Halocyptena microsoma Coues, Proc. Acad. Nat. Sci. Philadelphia, March- 

 April (June 30), 1864, p. 79. (San Jose del Cabo, Baja California.) 



