282 The Distribution of Spiders in the East Riding. 
8.—Pisidium cinereum Alder (=P. casertanum Bourg.) 
Habit: Isafjérdur, 1912, (Sikes). N.W. Iceland. 
9.—Pisidium personatum Malm. 
Habit: Faxaflbi, W. Iceland, (Steenstrup). 
10.—Pisidium milium Held. .. 
Habit: Gemlufallsheidi, Omundarfjérdur, N.W. Iceland, 
1913, (Schlesch). 
11.—Pisidium fossarinum Clessin. 
Habit: Isafjérdur, N.W. Iceland, 1913, (Schlesch), 
Granavatn, Mijvatn, N. Iceland, July 24th, 1913, 
(Seemundsson). 
var. flavescens Clessin. 
Habit: Isafjérdur, 1914, (Schlesch). N.W. Iceland. 
12.—Pisidium obtusale C. Pfeiffer. 
Habit : Thingvellir, S.W. Iceland, 1912 (Sikes), Laugaland 
in Skjaldfaunardalur near Drangaj6kul, 1913 (Schlesch). 
13.—Pisidium steenbuchit Moller. 
Habit : Thingvellir, S.W. Iceland, 1912, (Sikes), Botnvatn, 
Sudur Thingeyaryssel, N. Iceland, Aug. Ist, 1913 
(Seemundsson). 

THE DISTRIBUTION OF SPIDERS IN THE 
EAST RIDING. 
T. STAINFORTH, B.A., B.Sc., 
Hull. 
In view of the small number of workers and the large area 
to be covered, generalisations on the distribution of the main 
groups of Arachnida in the East Riding may seem somewhat 
premature. Temporary absence from the district, however, 
has led me to draw up the following notes, which include the 
results of my own collecting and that of others. 
It is obvious that generalisations on the distribution of a 
group of animals in a specified area are unsatisfactory until it 
has been exhaustively examined. The best or richest localities 
are very often those most thoroughly searched, and this is so 
in south-east Yorkshire (V.C. 61), some portions of which, 
particularly near Hull and in the south-west of the division 
have been well worked, whereas other portions, as along the 
northern and north-west boundary, have been neglected or 
visited only casually, owing to difficulty of access from the 
collectors’ bases. However, adopting the principle of ‘ ad 
Naturalist, 
