388 List of the Marine Mollusca of Iceland. 



* Cyrtodaria siliqua (Spengler). 

 Mya arenaria Linne. 

 truncata Linne. 



,, var. uddevallensis Forbes. 



LIST OF LITERATURE. 



GuDM. Bardarsson : Moerker efter Klima-og Niveauforand- 

 inger ved Hunafloi i Nordisland, Kobenhavn, 1910. 



R. Bergh : The Danish Ingolf-Expedition, Vol. II., Part 3, 

 Nudibranchiate Gasteropoda, Copenhagen, 1900. 



G. J. Jeffreys : British Conchology, London, 1863/69. 



Ad. Jensen : LamelUbranchiata from the Danish Ingolf- 

 Expedition, Copenhagen, 1912. 



O. A. L. MoRCH : Faunula Molluscorum Islandiae, Havniae, 1869. 



Nils Odhner : Marine Mollusca of Iceland, Stockholm, 1910. 



H. J. Posselt & Ad. Jensen : Gronlands Brachiopoder og 

 Bloddyr, Kobenhavn, 1899. 



H. J. Posselt : Ostgronlandske Mollusker, Kobenhavn, 1895. 

 G. O. Sars : Mollusca Regionis arcticae Norvegiae, Kristiania, 



1878. 

 H. A. Schlesch : Faunula Littorinidae Islandiae, Hull, 1916. 

 J. Sparre Schneider : Tromsosundets Molluskfauna, Tromso, 



1886. 

 0. Torell : Bidrag till Spitzbergens Molluskfauna, Stockholm, 



1859. 

 T. A. VERKRiiZEN : Schabe-Ausflug nach Island im Juni und 



Juli, 1872, Frankfurt, a/M 1872. 



Scarcity of the Wheatear, etc., in the years 1917 and 1918. 



— Much has been written regarding the changes in the status 

 of birds subsequent to the severe winter of 1916-17, but this 

 has had reference chiefly to our resident species, as was to 

 be expected. In this immediate neighbourhood one of our 

 earliest migrants, the Wheatear, which was, previous to the 

 summer of 1916, more or less common a breeding species, 

 has been almost totally absent. Indeed, for the last two sum- 

 mers, I have not found a single nest near Wilsden. I found 

 one nest in 1917 in a wall adjoining an old quarry near Shipley 

 Glen. I have often wondered whether this scarcity was merely 

 local or applied more generally to its breeding area. 



The Song Thrush, which was hit hard by the winter of 

 1916-17, recovered slightly, I think, last summer, but I fear 

 it will take many years, even if favourable years, before we may 

 expect to see it breeding again in its normal nuumbers. — 



E. P. BUTTERFIELD. 



Naturalist,. 



