The Greater Tern.'] OF ORKNEY. 12? 



" in swallows, who make the most sudden turn in the air of 

 " any birds, and all of them have forked tails." 



Where the sea-swallow retires to in winter I cannot say, 

 but it leaves us entirely when this season comes on ; probably 

 retires to the warmer climates. 



GENUS XXXI.—FETRELS. 



Gen. Char. — Bill straight, but hooked at the end ; nostrils cjlindric, tubular ; 

 tongue ; legs naked above the knees : back toe, none ; instead of it a sharp 

 spur pointing downwards. 



Species 1. — The Shear-Water. 



Manks Puffin, Wil. Orru 333. Rail Syn. Av. 134. Shear-Water, Idem, 1S3. 

 Procellaria Puffinus, Lin. Sys. 213. Brit. Zool 433. Manks Petrel, Brit. 

 Zool.fol. 146. Ore. Lyre. Avis Orcadensis Lyra dicta anate minor, et plu- 

 viali major, pinguissima, saporis pisculenti. Sib. Scot. 22. 



This bird is the chief acquisition our rock-men get for all 

 the danger in climbing the most dreadful precipices ; for this, 

 one sitting on the brink of the rock, with a coil of rope made 

 of hair on his arm, will let his neighbour many fathoms over 

 the steepest rocks, such as would make others shudder only to 

 look at, and yet these people think no more of it than an air- 

 ing ; and though fevv years pass without some or other of 



