98. PRION BANKSI (Smith). 



(BANK'S BLUE PETREL.) 



(Plate 83.) 



Pachyptila banksi, Smith, 111. Zool. S. Africa, Birds, PI. LV. (1849). 



Prion banksi, Gould, Ann. and Mag. Nat. Hist., XIII. , p. 366 (1844) ; id., Handb. 

 Birds Austr., II., p. 474 (1865) ; Gigl., Faun. Vertebr. Oceano, p. 44 (1870) ; 

 Buller, Birds New Zeal., p. 311 (1873) ; 2nd ed., II., p. 211 (1888) ; Salvin, 

 Cat. Birds Brit. Mus., XXV., p. 434 (1896) ; Sharpe, Rep. Coll. " Southern 

 Cross," p. 159 (1902) ; Wilson, Nat. Antarctic Exped., II., Aves, p. 106 

 (1907) ; Reichenow, Deutsche Siidpolar Exped., IX, Zool., I., p. 556 (1908). 



Prion rossii, Gray, List Anseres Brit. Mus., p. 165 (1844). 



Procellaria banksii, Schlegel, Mus. Pays-Bas, VI., Procell., p. 17 (1863). 



Pseudoprion banksii, Coues, Pr. Acad. Philad., 1866, pp. 166, 172. 



Pachyptila vittata (nee Gm.), Cab. and Reichenow, J. f. O., 1876, p. 328. 



Prion sp., Hume, Str. F., II., p. 317 (1874) ; V., p. 304 (1877). 



P. vittato similis, vix minor : pileo dorso concolori, vix fuscescentiore : sed rostro 

 debiliore, lateraliter minus arcuato, et lamellis maxillaribus minus obviis 

 distinguendus. 



Although there is very little real difference in colour between P. banksi and 

 P. vittatus, the former is of a paler blue-grey, and the head is more uniform 

 with the back, not dusky as in P. vittatus. The bill is bowed laterally towards the 

 tip, but is never so broad as in the last-named species : the lamellae, though always 

 present, are not so strongly developed, nor so much in evidence when the bill is closed. 



Specimens of P. banksi, in the British Museum, give the following measurements, 

 which may be compared with those of P. vittatus : — 



Length of Culmen. Breadth of Oilmen. Wing. Tarsus. Middle toe and claw. 



1.1-1.2 0.5-0.6 7.3-7.6 1.2-1.35 1.5-1.6 



Bank's Blue Petrel is stated by Gould (I.e.) to be found in the temperate latitudes 

 of both the Atlantic and Pacific Oceans. 



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