STORMY PETREL. 319 



Many nests may be found within the radius of a few 

 yards. 



RANGE OF EGG COLOURATION AND MEASUREMENT : 

 The Fork-tailed Petrel only lays one egg each season. 

 This is chalky in texture, very fragile, white in ground 

 colour, with a more or less obscure zone of minute red- 

 dish-brown specks, and a few underlying ones of grayer 

 brown. So fine are most of these markings that they 

 look almost like dust. Average measurement, 1*3 inch 

 in length, by '97 inch in breadth. Incubation, performed 

 by both sexes, lasts about thirty-five days. 



DIAGNOSTIC CHARACTERS : The eggs of this Petrel 

 are readily distinguished from those of all other allied 

 species breeding in our area by their size. 



Family PROCELLARIID^E. Genus PROCELLARIA. 



STORMY PETREL. 



PROCELLARIA PELAGICA, Linn&us. 

 Single Brooded. Laying season, June (normally). 



BRITISH BREEDING AREA : So far as is known the 

 Stormy Petrel does not breed anywhere on the eastern 

 coast-line of England or Scotland. It breeds on the 

 Scilly Isles, and is said to do so sparingly on Lundy ; 

 a few nest here and there on the Welsh coast, but it 

 becomes more generally distributed along the rugged 

 and islet-studded coast of the west of Scotland, in- 

 cluding the Hebrides and St. Kilda, and round the north 

 coast to the Orkneys and the Shetlands. There are 

 also numerous breeding-places round the Irish coasts, 

 especially in the west, including the Blaskets. 



