DYTISCUS. 
92 
also resides, which is of a very extraordinary shape, 
and is so utterly unlike the animal into which it is 
at length transformed, that no one inconversant 
in the history of insects would suppose it to have 
the most distant relationship to it ; since it much 
more resembles the insects of the slirimp tribe, 
and by the older writers, as Mouffet, Aldrovandus, 
&c. has actually been referred to that tribe of ani- 
mals, under the title of Squilla aquatica. It mea- 
sures, wdien full-grown, about two inches and a 
half in length,* and is of a pale yellowish brown 
colour, wdth a high decree of transparency: the 
liead is very large, somewhat flattened, and fur- 
nished in front w ith a pair of very strong, curved 
forceps, Avhich, when magnified, appear to be 
perforated at the tips by an oblong hole or slit, 
llirough which the animal sucks the juices of its 
prc}^: the legs are slender, of moderate length, 
and ]ilaccd on each side tlie thorax, the abdomen 
being lengthened out to a very considerable ex- 
tent, and finely fringed or ciliated on each side 
the tail, wdiich terminates in a most elegantly di- 
vided fin or process. This larva is of a bold and 
ferocious disposition, committing great ravages, 
not only among the weaker kind of w^ater-insects^ 
as well as w^ater-newts, tadpoles, &c. but even 
among fishes, of which it frequently destroys 
great numbers in a season, and is therefore justly 
considered as one of the most mischievous ani- 
mals that can infest a fish-pond. A larva of this 
kind has been known to seize on a young Tench 
of three inches in length, and to kill it in the 
