Roebuck : Semerdale. 



53 



highest summits are capped by millstone grit. The point of junction 

 between the base of the Yoredale rocks and tbe limestone below is 

 well marked on all the streams, more especially at Park Scar on the 

 Cragdale Water, by a series of beautiful waterfalls. The hills are 

 covered with coarse grass, or bents, and are much used for pasturage. 

 There is no heatherland, only very straggling plants of heather being 

 to be found. The district — once the famous Forest of Eaydale — is 

 now moderately wooded, especially up the Raydale stream. 



There is marshy ground at the foot of the lake, in which Parnassia 

 palustris grows abundantly, and through which, for the first mile of 

 its course, the Bain Hows with a very sluggish and muddy stream, 

 affording suitable stations for the growth of Potamogetons and the 

 yellow water-lily. Its course is afterwards much accelerated, and at 

 Bainbridge it dashes over shelving slabs of limestone, afterwards 

 joining the Yore opposite Askrigg. 



During the stay of myseK and some friends at Bainbridge, which 

 was our headquarters for the first fortnight of August, the vicinity of the 

 lake and both its shores, together with the three tributary dales, and 

 the slopes and summits of some of the hills, were visited. So far 

 as natural history was concerned, the only observations made were 

 upon the mollusca. Of other things I only recollect seeing specimens 

 of the fish I have before mentioned, finding a specimen of Cychrus 

 rostratus, and noting the water rat, peewit, magpie, dipper, frog, bull- 

 head or miller's thumb, the small garden white, small tortoise-shell and 

 small heath butterflies. 



The weather was not very favourable for mollusca, as there was no 

 rain whatever till nearly the last day of our stay, and shells were for 

 the most part somewhat difficult to find. I now give my list of shells, 

 all of which have passed the scrutiny of my friends Messrs. J. W. 

 Taylor and William Nelson, to whom I am indebted for assistance in 

 determining some of the more critical specimens, as well as confirming 

 my own determinations. 



An examination of the subjoined list at once shows that the species 

 of the montane or sub-alpine type are represented, usually in abun- 

 dance, and that the fluviatile forms are almost entirely absent. I 

 failed to detect any shells but Anodonta in the lake itself. The total 

 number, twenty-seven only, of species and varieties presents but a 

 meagre show, and my expectations of the capabilities of the district, 

 based upon its geological and physical aspect, were distinctly disap- 

 pointed, though there can be no doubt that further research at another 

 season of the year, or under more auspicious meteorological conditions. 



