284 STUDIES IN BIRD-MIGRATION 



Razorbill, Alca tarda. — Vast numbers visit the 

 islands as breeding-stations, arriving according to the 

 records, in some seasons late in February, and in others 

 late in March ; all had departed before we arrived on 6th 

 September 1904. 



Common Guillemot, Uria troile. — Many thousands 

 make their homes on the islands during the summer. 

 They are said to arrive from the middle of February to 

 the end of that month. They had quitted their summer 

 haunts before I arrived on 6th September 1904. 



Black Guillemot, Cepphus grylle. — See remarks on 

 this species at p. 263. 



Little Auk, Alle alle. — There are two records only 

 for the visits of this species. In 1903 one was seen on 

 13th December, and in 1909 one was found on 

 1 2th November. 



Puffin, Fratercula arctica. — :Described as being in 

 millions on the islands in summer. Arrives during the 

 latter half of April, and had left, with a few exceptions, 

 before our arrival on 6th September. See remarks on 

 this species on p. 263. 



Storm Petrel, Procellaria pelagica. — First noted 

 in the spring on 4th May, and latest in autumn for 

 1 8th October. Our observations on this species will be 

 found on p. 264. 



Fork-tailed Petrel, Oceanodroma leucorrhoa. — 

 This species has already been noticed, and our experi- 

 ences related on pages 264-5. The earliest notice in the 

 schedules for spring is for 6th April. The t.%% has 

 been found as early as 29th May. The light-keepers 

 aver that it captures moths at the lantern. 



Fulmar, Fulmarus glacialis. — Two pairs bred on 

 Eilean Mor in 1904 — the first instance of their breeding 



