8. OCEANODROMA CASTRO (Har court). 



(MADEIRAN FORK-TAILED PETREL.) 



(Plate 5.)* 



Thalassidroma castro, Harcourt, Sketch of Madeira, pp. 123, 166 (1851) ; id., Ann. 

 and Mag. Nat. Hist. (2), XV., p. 436 (1855). 



Thalassidroma jabe-jabe, Bocage, Jorn. Lisb., V., No. 18, p. 120 (1875). 



Cymochorea cryptoleucura, Ridgway, Pr. U. S. Nat. Mus., IV., p. 337 (1882). 



Oceanodroma cryptoleucura, Baird, Brewer, and Ridgw., Water Birds N. America, II., 

 p. 406 (1884) ; Ogilvie-Grant, Ibis, 1896, p. 53 ; Salvin, Cat. Birds Brit. Mus., 

 XXV., p. 350 (1896) ; Boyd Alexander, Ibis, 1898, p. 96. 



Oceanodroma castro, Sharpe, Handb. Brit. Birds, IV., p. 143, pi. CXI -' (1897) ; Ogilvie- 

 Grant, Ibis, 1898, p. 314 ; Rothsch. and Hartert, Nov. Zool., IX., pp. 415, 

 418 (1902) ; Godman, Biol. Centr.-Amer., Aves, III., p. 429 (1904) ; Hartert 

 and Ogilvie-Grant, Nov. Zool., XII. , p. 96 (1905). 



Procellaria cryptoleucura, Winge, Vid. Medd. Kjobenh., 1897, p. 246. 



O. leucorrhoce similis, sed cauda minus furcata, supracaudalibus late nigro terminatis ; 

 rectricibus, mediis exceptis, basin versus albis. 



This species is a form of O. leucorrhoa, with which it has often been confounded ; but 

 it is a somewhat smaller and blacker bird, having always black tips to the white upper 

 tail-coverts and a white base to the outer tail-feathers. These characters serve to 

 distinguish the two species, which would otherwise be somewhat difficult, for the 

 markings of the upper tail-coverts in O. leucorrhoa vary considerably, occasionally 

 showing dusky tips to the longer white tail-coverts. 



For many years this Petrel remained unrecognised, and it was chiefly due to the 

 description of O. cryptoleucura, from the Hawaiian Islands, by Professor Ridgway, that 

 attention was drawn to this species of Fork-tailed Petrel. A ftirther examination 

 of Mr. Harcourt' s description of O. castro led to the discovery that 0. cryptoleucura was 

 identical with the former species, of which a fine series of specimens has been obtained 

 in Madeira and the neighbouring islands by Mr. Ogilvie-Grant and Padre Schmitz, 

 as well as in the Azores by the first-named observer. Lieut. Boyd Alexander found the 



* The Plate has been lettered Oceanodroma cryptoleucura. It must be remarked that the light brown patch on 

 the wing should be more pronounced than it is in the illustration. 



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