NATURAL HISTORY 
OP THE 
BRITISH ENTOMOSTRACA. 
INTRODUCTION. 
In this monograph I have retained the name Entomo- 
straca, using it to comprehend all those minute Crustaceans 
described by Muller under that name, with the various 
additions which have been made since his time by 
Latreille, Leach, and others, to that particular group of 
curious little animals. To none of the Crustacea has so 
little attention been paid by British naturalists as this 
division, though there are few deserving of more attentive 
study. The exceeding minuteness, and the extreme de- 
licacy of structure of the great proportion of them, have 
perhaps been the causes of this neglect, deterring most 
naturalists from examining and studying them as they 
require to be studied — fresh from their native habitats. 
The difficulty of preserving them obliges the naturalist to 
seek them in their secret lurking-places, the fresh-water 
ponds and ditches, and the little pools in the rocks on 
the sea-shore, where they are chiefly to be found, or on 
the fishes to which they adhere as parasites, and to study 
them, as it were, upon the spot, with the aid of his mi- 
croscope. The external appearance, however, alone of 
many of these interesting little creatures is enough to 
excite the curiosity and rouse the attention of the natu- 
ralist. Some of them are so like small bivalve shells, 
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