MOLLUSCA IN THE NORTH OK SCOTLAND 



Reverting to the vagaries of distribution of mollusca in the 

 parts of Scotland visited, the genus Hyalinia was commoner on 

 the west than on the east side. Also Hygromia granulata, 

 Acanthtnula lamellata, and Pupa anglica occurred on the west 

 coast only. Admitting that the west coast had the more favourable 

 conditions to offer, does not explain why Helicigona arbustorum 

 and Helix hortensis were so abundant on the east and so sparingly 

 found on the west coast. In the case of the last-named it may be 

 said to be rare on the west side, where only odd specimens were 

 found in numerous localities where it might have been expected to 

 occur commonly. 



Helicella caperata inhabited the sandhills of Belhelvie, yet there 

 were equally favourable grassy slopes on the west where one would 

 expect to find it. 



It is a matter difficult to explain why Succinea elegans was so 

 abundant on the Aberdeenshire coast but so sparingly distributed 

 on the west and absent from Skye during the present investigation, 

 as habitats similar to those which it inhabited on the east were 

 more numerous on the west; and to me the observations add to 

 the difficulty rather than to its elucidation. 



In regard to fresh-water species very little can be said. Though 

 there are numerous lochs throughout the different areas .investigated, 

 they are so situated that valuable time would be lost in going to 

 them, as in most cases the ways leading to them are through parts 

 of the country unsuitable for finding land species. The lochs that 

 were investigated proved very barren, three small ones in the 

 Gairloch district failing to produce anything, even the common 

 Limncea peregra being absent. Loch Gill Chriosd on the Torran 

 road, Broadford, was also devoid of shell-life, which seemed quite 

 unaccountable, as it was three parts covered by reeds and water- 

 lilies. Examination of the margin and of the debris washed up on 

 it failed to produce evidence in the form of dead shells. In small 

 streams that ran into the loch there occurred Limncea peregra and 

 Ancylus flitviatilis, both very scarce, as to all appearance recent 

 floods had greatly disturbed the bed of the streams. Limncea 

 truncatula and some species of Pisidium inhabited the ditches near 

 the loch. Most of the rivers and streams being in spate, it was a 

 difficult matter to make a thorough examination of them for 

 mollusca. Unto margaritifer appeared to be abundant in the 

 Kerry River, near Gairloch, judging by the quantity of dead shells 

 washed up along the margin, also in the river Ugie in Aberdeenshire ; 

 but in each case the swollen state of the water made it impossible 

 to find living examples. 



