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SOME RESULTS OF A SURVEY OF THE AGRICUL¬ 
TURAL ZOOLOGY OF THE ABERYSTWYTH AREA. 
By CHAS. L. WALTON, M.Sc. (Wales). 
(Departments of Zoology and Agriculture, University College 
of Wales, Aberystwyth.) 
During the period 1913—16,1 conducted a Survey of the Agricultural 
Zoology of the Aberystwyth Area, for which purpose the University 
authorities received a grant from the Board of Agriculture. The area 
thus examined comprised N. Cardiganshire and some adjacent borders 
of Montgomeryshire, roughly about 250 sq. miles. It falls into three 
main physical divisions: 
I. The mountainous upland (or high plateau) of solid rocks fre¬ 
quently covered by a considerable depth of peat. The rock succession 
is only irregularly exposed in deep stream cuttings, while these valleys 
are occupied by boulder clay and river deposits. 
II. The surface of the coastal plateau shows exposures of rock 
and of boulder clay. The clay is usually exposed and rarely covered 
with peat. 
III. The fall line, which is intermediate. Here the boulder clay 
generally follows the valleys, and it is usually covered with a thin layer 
of peat. Much of this is readily cut through by small streams. 
The Dyfi Flats (or Bortli Bog) form a distinct type consisting largely 
of peat but with a few well-defined tracts of tenacious clay (alluvium). 
To the south-east of the area are large districts floored entirely by boulder 
clay, and ill-drained. 
The high plateau is the great summer grazing area for sheep; the 
fall line or slope between it and the lower coastal plateau is of con¬ 
siderable extent and importance and includes much of the woodland of 
