THE HYDRADEPHAGA 
OF LANCASHIRE AND CHESHIRE. 
A PAPER READ BEFORE THE saber c3: Society OF LANCASHIRE AND CHESHIRE, 
Frepruary 8TH, 1892 
< e SR ARE, 
Ledsham, Cheshire. 
**DosT KNOW THIS WATER-FLY?”—Hamilet. 
SINCE the days of Linnzeus and the dawn of the systematic study of 
nature, the order Coleoptera has been primarily divided into certain 
large groups or sub-orders, which in value perhaps oa with 
those sections of the Lepidoptera which we call Butterflies pt 
1 been based o 
different characteristics. Linnzeus recognised in the antennz a Seem 
of primary importance; eas poy the great Latreille, insisted on 
the number of tarsal joints; but in all the systems the group 
Adephaga, as it is called, or As devourers, has always been assigned 
the first place among the beetles. This group has been generally 
which the order has attained, and as the Coleoptera head the Class 
Insecta, and Insecta the sub-kingdom Articulata, so from one point 
of view, we might assert that this group of Adephagous tt 
exhibits the topmost pinnacle of organic elaboration, which so far 
on this earth, has been reached by the Articulata. Now without 
expanding into a dissertation on the peculiarities of the structure of 
this group, we will merely say that it is divided into two great sections, 
the Geodephaga, or devourers of the earth, the Hydradephaga, or 
aevourers of the water, and it is this latter section, the Hydra- 
dephaga, which I propose to consider more particularly in this paper. 
These beetles then are, as we may say, that extension of the 
structure, to meet the demands which such an environment imposes. 
Ve must not allow ourselves to imagine that the whole group was 
originally aquatic, and that the Geodephaga are Hydradephaga which 
have taken to a terrestrial life. The reverse is the case. Coleop- 
terous life undoubtedly began not in the waters, but on the earth ; 
portions of the order have since its divergence become aquatic and 
semi-aquatic ; and just as the highest point of complexity of 
e 
terrestrial forms of Coleoptera is to be found among the Geodephaga, 
June 1892. 
