STORM-PETREL. 137 



two are British, viz., Procellaria and Oceanodroma. The third, 

 Halocyptena, is only found off the west coast of North America, 

 from California to Panama, and contains but a single species, 

 H. microsoma. 



THE STORM-PETRELS. GENUS PROCELLARIA. 

 Procellaria, Linn. Syst. Nat. i. p. 212 (1766). 



Type P. pelagica (Linn.). 



In this genus the tarsus is longer than the middle toe and 

 claw, and the tail is rounded or nearly even, never forked. 

 Only two species of Procellaria are known, P. tethys being 

 confined to the seas of the western coast of South America. 



1. THE STORM-PETREL. PROCELLARIA PELAGICA. 



Procellaria pelagica, Linn. Syst. Nat. i. p. 212 (1766) ; B. O. U. 



List Brit. B. p. 196 (1883); Saunders, ed. Yarrell's Brit. 



B. iv. p. 42 (1884) ; Seebohm, Hist. Brit. B. iii. p. 438 



(1885); Saunders, Man. Brit. B. p. 727 (1889); Salvin, 



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

 Thalassidroma pelagica, Macgill. Brit. B. v. p. 460 (1852); 



Dresser, B. Eur. viii. p. 491 (1874). 



(Plate CXIa.} 



Adult Male. Sooty-black above and below, with more or 

 less of a greyish shade ; rump and sides of lower back white ; 

 upper tail-coverts white, tipped with black ; wing-coverts sooty 

 black, the greater series narrowly but plainly edged with white ; 

 quills and tail black ; under surface of body sooty brown, 

 shaded with grey over the head and face, as well as on the 

 throat and chest ; under tail-coverts sooty black, the lateral 

 ones white with black tips ; under wing-coverts sooty black, the 

 median series broadly edged with white ; bill, legs, and feet 

 black ; iris hazel. Total length, 6 inches ; culmen, 0*5 ; wing, 

 4-75 ; tail, 2 -i ; tarsus, o'8. 



Adult Female. Similar to the male. Total length, 6 inches; 

 wing, 4-8 



Nestling. Enveloped in sooty down, the feathers as they are 

 developed being exactly like those of the adults. 



