YORKSHIRE NATURALISTS’ UNION 
FRESHWATER BIOLOGY COMMITTEE. 
The Annual Field Meeting will be held at RIPON on the occasion of the 
Union Meeting there, August 5th-7th, 1933. 
Time and Place of the Business Meeting will be posted at Headquarters. 
28 Grosvenor Terrace, CHARLES ALLEN, 
York. Convener. 
W. H. JANSON & SON 
44 GT. RUSSELL STREET, LONDON, W.C.l 
ALL REQUISITES FOR NATURALISTS 
Catalogue sent free. 
BINDING “ THE NATURALIST ” 
Volumes of THE NATURALIST for 
any year can be bound in a serviceable 
and attractive Cloth Case , dark blue 
and gilt lettered on back and side. Price 
4/- per volume, or post free 4/6. 
A.. BROWN & SONS, LIMITED 
PERTH STREET WEST, HULL 
FOR SALE. 
GEOLOGY. 
At 3/- each. 
Researches in Newer Pliocene and Post-Tertiary Geology. J. Smith. 
Slate and Slate Quarrying. D. C. Davies. 
Valleys and Their Relations to Fissures, etc. G. H. Kinahan. 
The Ventriculidae of the Chalk (Plates). J. Toulmin Smith. 
At 3/6 each. 
The World Before the Deluge. Louis Figuier. 
The Student’s Elements of Geology. Sir Charles Lyell. 
An Introduction to Petrology. F. P. Mennell. 
Geology of East Norfolk. R. C. Taylor. 
Catalogue Raissonne des Dufferens effets Curieux 1766. Helle and 
Glomy. 
A Sketch-Map Geography. E. G. R. Taylors. 
Volcanoes and Earthquakes. Houston. 
At 4/- each. 
Elements of Mining and Quarrying (2nd Ed.). C. Le Neve Foster. 
At 4/6 each. 
The Student’s Manual of Geology. J. Beete Jukes. 
A Manual of Petrology. F. P. Mennell. 
Geology of Clydesdale and Arran. James Bryce. 
Geological Fragments Collected at Furness and Cartmel. J. Bolton. 
The Geology of Arran and the other Clyde Islands. James Bryce. 
Autobiographical Sketch of James Croll. J. C. Irons. 
Life and Letters of Sir Joseph Prestwich. G. A. Prestwich. 
Geology (2 Vols.) D. T. Ansted. 
Apply : — C Department, Messrs. A. Brown & Sons, Ltd. 
