SULE SKERRY AND ITS BIRD-VISITORS 295 



Luckily it was placed in spirit, and sent to me in the 

 flesh, by the next relief steamer visiting the island, 

 otherwise the species would have escaped detection within 

 the British area for some years. The whole of the 

 circumstances relating to the occurrence of this incon- 

 spicuous little bird on that remote Atlantic rock, where, 

 by the merest chance, it was saved from oblivion, 

 forcibly remind us how very many similar cases there 

 must be annually of migrants escaping notice, including 

 the great majority of the commonest species — a fact 

 that unfortunately many interested in the subject of 

 migration do not fully realise, and hence the rash 

 speculations which are raised on the very flimsiest of 

 foundations. 



Troglodytes troglodytes. Common Wren. — One 

 appearance on the island, in September 1900, is the only 

 known visit. 



MuscicAPA ATRiCAPiLLA, Pied Flycatcher, — Single 

 birds have occurred on three occasions — twice in 

 September and once on 5th November 1901, The 

 latter is a very late date for the appearance of this species 

 anywhere in the British Islands. 



HiRUNDO RUSTicA, Swallow. — According to Mr 

 Tomison, a few are seen every year in May and June. 



Chelidon urbica, House-Martin. — A casual visitor 

 whose appearance has been recorded on four occasions. 

 These are i6th May, 15th June, 22nd June, and 27th 

 August, and four is the largest number observed. 



CoTiLE RiPARiA, Saud-Martin. — One is recorded for 

 2ist May 1910. 



Cypselus apus. Swift. — There are nine recorded 

 appearances of this species, eight of which were in 

 August, at dates ranging from 1 2th to 30th ; and one on 



