286 THE SCOTTISH NATURALIST 



The most important paper is the one in which Messrs Jas. 

 Waterston and J. W. Taylor embodied the former's work of 

 June and July 1905 upon the " Land and Freshwater Molluscs 

 of St Kilda" {Ann. Scot. Nat. Hist., January 1906, pp. 21-24), 

 in which they listed 21 species and various varieties, with 

 notes upon their range and habitats. In the same number 

 of the Annals Mr Waterston gave an account of the 21 

 species he collected the same year at Balelone in North Uist. 

 In the Scottish Naturalist for 191 5, p. 336, Mr W. Evans 

 recorded 4 species he had received from the Butt of Lewis. 



My own " Census of Scottish Land and Freshwater 

 Mollusca" {Proc. Roy.PJiys. Soc, Edinburgh, vol. io, 1889-90, 

 pub. 1 891, pp. 437-503) gives localities for 15 species. 



Dr F. Buchanan White's List of Scottish Land and 

 Freshwater Mollusca (Scot. Nat., vol. 2, 1873) has no 

 references to the Outer Hebrides. 



Species which have been .seen and recorded, but not 

 "authenticated" and consequently not includable in the 

 present list, include Avion hortensis and Agriolimax lewis. 

 I shall be very pleased to see living examples of these, and 

 of any other species from any part of the archipelago, which 

 may be addressed to me at 259 Hyde Park Road, Leeds. 



Yellow Wagtail in Bute. On 17th May 19 18 I saw a female 

 Yellow Wagtail {Motacilla rail) in close attendance on a grazing 

 stirk in a field near the shore at Kilchattan Bay. Apparently 

 it was on passage, as I failed to see it again. This was the first 

 time I had observed the Yellow Wagtail actually on the ground 

 in Bute, but on 17th May 1909 I saw a single bird passing south- 

 west, and on 19th May 1910 another going south-east, over 

 Kilchattan Bay, without alighting. (The closeness of the days 

 of the month in the three years is noteworthy.) As the Yellow 

 Wagtail is tolerably common in Ayrshire in summer, and, in some 

 autumns at least, abundant close to the shore from Fairlie south- 

 wards, it would seem that here is an instance of a narrow arm of 

 the sea presenting a fairly effectual barrier to a species and that 

 a highly migratory one. (See the Rev. J. M. M'William's observa- 

 tions, p. 27 of the current volume.) John Roisertson, Glasgow. 



