142 ^NATURAL HISTORY OF 
perform tlieir cheerful circlings in separate family 
associations. If we interfere with tlieir merriment 
they seem greatly alarmed, disperse, or dive to the 
bottom, when their fears shortly subside, as we soon 
again see our little merry friends gamboling as be- 
fore. This plain, tiny, gliding water-flea seems a 
very unlikely creature to arrest our young atten- 
tions ; but the boy with his angle has not often 
much to engage his notice, and the social active 
parties of this nimble swimmer, presenting them- 
selves at these periods of vacancy, become insensibly 
familiar to his sight, and by many of us are not ob- 
served in after life without recalling former hours, 
scenes of, perhaps, less anxious days ; for trifles like 
these, by reason of some association, are often re- 
membered, when things of greater moment pass off 
and leave no trace uuon the mind."* 
CYCLOUS VITTATUS. 
PLATE IV. Fig. 3. 
This insect exemplifies an exotic group, very 
closely related to the Gyrini, but offering so many 
minute modifications of structure as to warrant their 
separation into a distinct genus. The most obvious 
difference is the want of an apparent scutellum in 
Cyclous, the great size of the body, and the length 
Journal of a Naturalist. 
