100 Proceedings of the Royal Physical Society. 



woods. In the former localities, on the banks of the Meuse 

 near Dinant in Belgium, I have found it attaining the 

 dimensions of an average-sized Helix nemoralis. The speci- 

 mens which I now submit to the Society do not reach half 

 that size, are of a much lighter colour than that of the 

 typical shell, and have the spire more raised and almost 

 subconoidal. This is, I believe, the Helix alpestris of 

 Zeigler. The animal, in most of the examples observed, 

 instead of being of the usual leaden or greyish-green colour, 

 was light-brown or drab. 



I found this well-marked variety during a geological ex- 

 cursion in company with Mr E. L. Jack, of the Geological 

 Survey, in Glen Shirrup, a little below the 1750 feet contour 

 line of the Ordnance Map, feeding, in considerable numbers, 

 in nettle beds on the bank of the stream, one of the affluents 

 of the Devon. All the adult individuals were of the same 

 form and dimensions. 



As H. arhustorum is known to be one of the most Alpine 

 of our Helices on the Continent, extending its range nearly 

 to the summits of the Vosges and Jura, and even passing the 

 snow-line in the Swiss Alps, there is nothing remarkable in 

 the fact of its being found at the above-mentioned altitude ; 

 but not having found mention made of its occurrence in the 

 Ochils, the communication of the foregoing observations may 

 be of interest to the Society. 



lY. — On the Employment of Arsenic in the manufacture of 

 Wall Papers. By J. Falconer King, Esq., City Analyst. 



As the result of certain experiments, Mr King found that 

 not only expensive papers, and those which contained green, 

 but the great bulk of cheap papers and those of the duller 

 colours without a trace of green, contained arsenic in an ap- 

 preciable degree. 



V. Mr Herbert exhibited a series of Bird Skins from 

 Transvaal and Natal, on which some remarks were made by 

 Mr Gray. 



The Society then adjourned to the third Wednesday in 

 November. 



