MONOGRAPH OF THE PETRELS. 



lay becalmed about five miles off the island, only two skins were prepared, as it was 

 then supposed to be a well-known species. 



Professor Giglioli points out in his essay on the geographical distribution of the 

 vertebrates of the southern ocean, that this species, though bearing some relation to 

 CE. mollis, is smaller and more slender in appearance, and is without the white 

 forehead. 



The Earl of Crawford brought back a specimen of this Petrel which was killed 

 with a stick on South Trinidad Island in 1874, and was erroneously ascribed by 

 Howard Saunders to CE. mollis. 



Dr. Wilson, of the " Discovery," procured light and dark specimens from the 

 same island in September, 1901, and Dr. Sharpe, believing the latter to be distinct, 

 named it CE. wilsoni (B. 0. C, XII., p. 49, 1902). He compared it with CE. 

 arminjoniana, but found it was darker, and had a larger bill. Dr. Wilson mentions 

 that the birds were very abundant, and nested on the island, some having dark 

 breasts, while others were white beneath, but all had pink legs and feet. 



Mr. Nicoll, who accompanied Lord Crawford on a second visit to South Trinidad 

 Island in 1905, and procured examples of both light and dark birds, throws doubt on 

 their belonging to different species. He thought that the dark birds were immature, 

 but inasmuch as many were breeding, it is evident they were adult. After examining 

 the series in. the British Museum, which contains both forms, I have come to the 

 conclusion, in which Dr. Sharpe agrees, that they belong to the same species, and 

 they must therefore bear the name of (E. arminjoniana. The dark form is very similar 

 to CE. trinitatis, but the latter may always be distinguished by its black legs and feet ; 

 in CE. neglecta the tarsi and base of the webs are yellow. 



There is a young bird in the downy stage in the British Museum in which white 

 feathers are appearing on the breast, showing that the dark plumage does not indicate 

 an immature bird. 



According to Dr. Wilson, the nest is only a saucer-like depression placed on a 

 ledge in the soft rock, where the single white egg is deposited. On skinning one of 

 these Fulmars, he observed a capacious hollow in the abdomen sufficiently large to 

 hold the egg, which is as big as that of a fowl : — Axis, 2.4 inches ; diam., 1.75. 



Adult male. General colour above ashy-black, the feathers of the back from 

 the nape downwards mottled with white bases ; scapulars and wing-coverts blackish, 

 washed with slaty-grey, the greater coverts for the most part slaty-grey, with dusky 

 margins ; quills dusky-black, ashy-brown for the greater part of the inner web, the 

 secondaries blackish for the greater part, ashy-brown towards the ends of the inner 

 webs, or mottled, with blackish vermiculations, mostly at the end of the outer web ; 

 upper tail-coverts and tail blackish, with a slight ashy shade ; crown of head and sides 

 of face like the back, the feathers below the eye and the ear-coverts slightly mottled 

 with white bases to the feathers ; throat white, slightly mottled, with dull ashy bars, 



230 



