PEOCELLARIA. 427 



Three genera of this subfamily are included within our limits— Procellaria, Ealo- 

 cyptena, and Oceanodroma. They are inhabitants of the Atlantic and Pacific Oceans, 

 chiefly north of the Equator, with the exception of Halocyptena, which is confined to 

 the Eastern Pacific, from the Galapagos Islands to the coast of Central America. 



PROCELLAEIA. 



Procellaria, Linn. Syst. Nat. i. p. 212 (1766); Cones, Proc. Acad. Philad. 1864, p. 79; Salvin, 

 Cat. Birds Brit. Mus. xxv. p. 343 (1896). 



The type of the genus Procellaria is the well-known " Storm-Petrel," or " Mother 

 Carey's Chicken," which is widely distributed throughout the Atlantic Ocean, breeding 

 north of the Equator. It is distinguished from Oceanodroma, of which Leach's Petrel 

 {0. leucorrhoa) is the type, by its longer tarsus, which exceeds the length of the middle 

 toe and claw, while the tail has no distinct fork. 



Only two species are recognized, the common P.pelagica and P. tethys, with the 

 latter of which we are alone concerned. 



1. Procellaria tethys. 



Thalassidroma tethys, Bp. J. f. Orn. 1853, p. 47 ^ 



Procellaria tethys, Towns. Proc. U. S. Nat. Mus. xiii. p. 142 ""; Salv. Cat. Birds Brit Mus. xxv. 

 p. 346 ' ; Eothsch. & Hart. Nov. Zool. vi. p. 199 '; ix. p. 416 \ 



ruliginoso-brunnea, vix sehistaceo adumbrata ; uropygio et supracaudalibus pure albis ; alis caudaque nigris, 

 tectrioibus majoribus omnibus et secundariis nonnullis intimis extus clarius brunneis, plagam alarem 

 formantibus : subtus fuliginoso-bruunea, subalaribus medianis et majoribus vix pallidioribus, chocolatinis ; 

 subcaudalibus lateralibus extus albis : rostro et pedibus nigris ; iride saturate brunnea. Long, tota 

 circa 6-0, alse 5-3, caudse 2-25, culm. 0'5, tarsi 0-85. (Descr. maris adulti ex Culpepper I. Mus. Brit.) 



5 ad. mari similis. Long, tota circa 5'8, alae 5'2. (Descr. feminae adultse ex Wenman I. Mus. Brit.) 



Hob. West Coast of Central America ^. — Galapagos Is. ^ ^ ^. 



This small Petrel probably occurs on the west coast of Central America, as stated 

 by Salvin ^, though we do not know what evidence he had for this statement. 



Messrs. Rothschild and Hartert say that P. tethys was found during the Webster- 

 Harris expedition to the Galapagos Archipelago in the seas round the islands of 

 Wenman, Culpepper, Albemarle, and Tower 4; and more recently Mr. Beck has 

 procured specimens in the neighbourhood of Bindloe, North Albemarle, and at sea 

 in r N. lat., 39° W. long.^ It was far more abundant in the northern part of the 

 archipelago than in the south, and was generally met with far out at sea ^. Mr. C. H. 

 Townsend found examples of this Petrel in lat. 40° 22' N., long. 82° 32' W., and 

 about 400 to 600 miles east of the Galapagos 2. 



The species will doubtless be found to breed on some of the last-named islands. 



54* 



