Yorkshire Naturalists in Coverdale. 297 
which occurred in the district; as remarkable for their occurrence 
in the British Isles and West-Central Europe. The features 
of the flora in general were also commented upon. 
Dr. T. W. Woodhead, M.Sc., discoursed upon _ the 
life history of the Purple Heath Grass (Molinia cerulea) in the 
Huddersfield district. He explained that the details of its 
distribution, and of the anatomy of the plant had been worked 
out by one of his students, the Rev. T. A. Jefiries, and 
recently published. The morphological features of the 
plant, and the factors affecting its distribution on the moorland 
areas, and in the woods of the Huddersfield district, were 
described, as well as the chief competitors of the grass under 
certain conditions of growth. 
Mr. B. Hobson, B.Sc., gave an interesting account of his 
investigations of the underground watercourses of the lime- 
stone areas, especially dealing with those in the district of 
Ingleborough, the geological features of which he lucidly 
explained. He particularly mentioned the repeated disappear- 
ance of Dale Beck, and also of disappearing streams in 
Dentdale, and in the early sources of the rivers Wharfe, 
Aire and Skirfare. His remarks were illustrated by geological 
maps.—W.E.L.W. 
CoNncHOLoGy.—Mr. Greevz Fysher reports :— 
All the shells I collected have been seen by Mr. J. W. 
Taylor, and the slugs by Mr. W. Denison Roebuck. At Slade 
Gill, Coverham, were found Arion circumscriptus, Pvranndula 
votundata and a fine trochoidal example of Helicigona arbus- 
torum. At Coverham Abbey were found Agriolimax agrestis 
v. reticulata, one Zua lubrica, a few Hygromia hispida and 
numerous Hf. rufescens. At Scrafton was abundance both of 
Clausilia bidentata and Cl. cravenensis, one H. rufescens, two 
Pyramidula rupestris, and a typical example of Limax arborum. - 
At Middleham Helix aspersa was in abundance, Agriolimax 
agrestis and H. rufescens were numerous, together with a few 
each of Balea perversa, Cl. bidentata and Hygromia hispida, 
and one Hyalinia cellaria. On West Witton Fell were found 
fine adult examples of Limax cinereo-niger var. luctuosa and 
L. maximus var. fasciata, the type of Avion ater, an adult A. 
circumscriptus, a half-grown H. arbustorum, an immature 
H. hispida var. rubens, one Azeca tridens, one Cl. bidentata, and 
a few Clausilia laminata. This makes a total of five slugs and 
thirteen land shells for the Lower Coverdale area planned for 
special investigation. Other captures were Helicella cantiana 
and its reddish form in great abundance at Melmerby, near 
Ripon, H. itala in plenty together with H. rufescens and its 
var. rubens and P. rotundata at Leyburn; and Hyalima 
cellaria (two adults), C!. bidentata, and a fine example of H. 
aspersa at Wensley. 

1916 Sept 1. 
