Y.N.U. Exhibition at the British Association. 363 
Distribution of some aquatic and semi -aquatic mosses in the watercourses 
of millstone grit and limestone areas : Species characteristic of Water 
rich in Lime : Weisia verticillata, Hypnum commutatum , Hypnum virescens. 
Species characteristic of Water poor in Lime : Rhacomitrium aciculare, 
Hyocomium flagellare, Bracyhthecum plumosum, Hypnum ochraceum. 
(4) The Moss Flora of an Industrial City, by Mr. W. H. Burrell. (5) 
The Oil Bodies of Liverworts, by Mr. F. E. Milsom. Microscope 
slides showing oily masses of various sizes suspended in the cell -cytoplasm 
of liverworts. Their composition is commonly a fatty oil sometimes 
mixed with essential oil. 
( d ) Yorkshire Mycological Committee. — Exhibits: (1) The survey 
work of the Committee by means of a map and flora, and contributions 
to the literature of mycology by Yorkshire workers, commencing with 
Bolton's ‘History of Fungusses Growing About Halifax,’ written in 
1775. ( 2 ) Photographs of groups of members taken at Forays (A. E. 
Peck and others ) . These have a bearing on the history of the Committee 
and on the inauguration of the British Mycological Society, which was 
founded at a meeting of the Yorkshire Naturalists’ Union at Selby in 
1896. (3) Photographs of Fungi, A. E. Peck. (4) Stereo photos of 
Fungi, A. Clarke. (5) Drawings of Fungi, Sir Henry Hawley, Bart. 
(6) A Series of Lantern Transparencies of Mycological interest. (7) A 
Collection of Parasitic Fungi mounted as museum specimens. (8) A Tri- 
dimensional Graphic Key to Genera of the Agaricacese, F. A. Mason. 
Section F (Geology) : — 
Exhibits by Mr. H. C. Versey, M.Sc. — (1 ) Specimens and Microscope 
sections illustrating the Petrography of the Millstone Grit of Yorkshire, 
by Prof. A. Gilligan ; (2) Map showing the position of the small folds 
in the Yorkshire Chalk and their position in alignment with certain of the 
pre -cretaceous folds seen in the Jurassic rocks to the west ; (3) Micros- 
copic slides and specimens illustrating the mineralogy and petrology of 
the sandstones and conglomerates of Permian age in Yorkshire. 
{a) Geological Photographs Committee . — Exhibits : Volumes of 
Geological Photographs of Yorkshire. 
(b) Yorkshire Glacial Committee . — Exhibits : Maps showing distribu- 
tion of Erratics and Drift in Yorkshire. 
(c) Yorkshire Coast Erosion Committee. — Exhibits: Maps and 
Photographs illustrating Coast Erosion in Yorkshire. 
(d) Carboniferous Rocks, Fossil Flora and Fauna Committee . — (1) 
Exhibit by Mr. W. S. Bisat, Hull. A series of goniatites . shewing the 
species characterising (in Yorkshire) the various zones of the Carbonifer- 
ous Rocks from the Mountain Limestone up to the Lower Coal 
Measures. (2) A specimen of Calamites, exhibited by Miss M. A. 
Johnstone. (3) Exhibit by Mr. W. R. Barker, Barnsley : (i.) Marine 
shells from horizon of the Mansfield Marine Band, 1,080 feet above the 
Barnsley coal, from claypit at Monk Bretton, Barnsley ; the exposure, 
which shews soft shales with marine fossils on a thin limestone, is 
notable as greatly extending the known horizontal extent of this important 
marine band, (ii.) A new plant from the. same locality, 15 feet below 
the Marine band, (iii . ) A rare crustacean, Anthropaloemon, from shales 
over the Tankersley Ironstone. 
(e) Jurassic Flora of Yorkshire. — Exhibit of work in the Yorkshire 
Jurassic Flora by Mr. H. Hamshaw Thomas, M.A., Pembroke College, 
arranged to show (i.) New Methods of Study of the Material ; (ii.) The 
elucidation of the affinities of the plants by the discovery and study of 
their reproductive structures ; (iii. ) Evidence of Angiosperms in Jurassic 
Times ; (iv.) Some recently discovered genera and species new to science ; 
(v.) The geographical distribution of plant beds in Yorkshire, with 
specimens from the recently discovered beds in the Cleveland District. 
Mr. Thomas demonstrated new methods of obtaining undamaged speci- 
1922 Nov. 1 
