293 



MOLLUSCAN FAUNA OF LANQSTROTHDALE. 



W. DEMSON ROEBUCK, F.L.S. 



CoN'CHOLOGiCALLY the results obtained during- the Yorkshire 

 Naturalists' excursion to Buckden for Lang-strothdale were so 

 satisfactor}' that, tog"ether with other material contributed by 

 the Rev. Trevor Basil Woodd, B.A., they will be most usefully 

 put into the form of a List of the Mollusca of Lang-strothdale. 



The district appointed for investigation was a very compact 

 and well-defined one, consisting- of the extreme upper part of 

 Wharfedale from Starbotton northwards to the sources of the 

 two becks, Oug"htershaw and Greenfield Becks, which unite 

 under the name of Wharfe at Beckermonds. 



It is a mountain region, no part of it falling below 730 feet 

 in elevation, and its mountain barriers on either side rising to 

 a g-eneral level of about 1,800 feet, and culminating' on one side 

 at the fine summit of Buckden Pike (2,302 feet) and on the 

 other at 2,001 feet on the Horse's Head. 



Geologically it is entirely a limestone area, the fine scars of 

 the Great Scar Limestone, and the fine woodlands which clothe 

 the slopes, and the rich vegetation of the deep gills which 

 cleave the mountain sides, combining to make the district a rich 

 hunting-ground for conchologists. 



The conchologists present throughout the whole three days 

 of the excursion were Mr. John W. Taylor, Mr. T. Fetch, B.Sc. , 

 and myself. 



The first day's exploration was of the neighbourhood of 

 Oughtershaw, and the roadsides on the way to it. The tarn 

 on Oughtershaw Moor, 1,800 feet, and a pot-hole close to it, 

 were examined but with negative result. 



The second day was spent in the investigation of the slopes 

 of the mountain, Buckden Pike, Mr. Taylor and I making the 

 ascent from Starbotton, noting the mollusca and their altitudes 

 as we ascended, while Mr. Petch, with his usual painstaking 

 industry, searched Buckden Gill. All of us on our return 

 searched the vicinity of Cray and the subsidiary Crook Gill. 



The third day was devoted by all of us to the careful investi- 

 gation of Buckden Wood and the gills which intersect it, an 

 exceedingly rich hunting-ground which would repay further 

 search. 



Our material was added to partly by a small collection which 

 I made in the wood last March, and by a number of shells 



1904 October i. 



