BRITISH BIRDS. 199 



and tapering, but much shorter than in the next species. 

 Length 19*00; wing I3'5o; shafts of all the primaries 

 are white at all ages. 



Breeds on the Shetlands, Orkneys, Hebrides and a few 

 spots in the Highlands ; also of frequent occurrence in 

 winter on all our coasts. Eggs : 2 ; olive-green, blotched 

 and spotted with deep brown ; 2*30 by 1*60. 



334. Stereorarius parasitieus (Linn.). LONG- 

 TAILED SKUA. 



Hab. Circumpolar regions. 



Adult : smaller and more slender than S. crepidatus, 

 and with shafts of 2 outer primaries only white ; upper 

 parts and belly greyish-brown ; head nearly black ; neck 

 dull yellow ; breast white. Length to tip of tail 22'oo ; 

 wing 11*75. Female has a rather shorter tail. 



An irregular autumn visitor, sometimes occurring in fair 

 numbers on the east side of Great Britain. 



ORDER TUBZNARES. 

 Family Procellariidae. 



GENUS CXCIII. PROCELLARIA, Linnsus 0766). 



Bill moderate, straight, excepting the horny nail at tip, 

 which is much decurved. Nostrils tubular, placed upon 

 upper surface of bill. Wings long, narrow. Tail moderate, 

 nearly even. Tarsi moderate ; hind toe obsolete. 



355. Proeellaria pelagiea, Linn. STORM-PETREL. 



Hab. Atlantic coasts of Europe ; also Mediterranean. 



Adult : plumage black, excepting upper tail-coverts and 

 sides of rump, which are conspicuously white ; bill and 

 feet black. Length 5*25 ; wing 4-65. 



