DYTISCUS. 
93 
space of about a minute; and even the Banstickle 
itself, which is so great a destroyer of the small 
fry of fishes, and so well armed for defence, is not- 
withstanding a prey to this devouring insect, which 
seizes it with violence, and very quickly destroys 
it. When. arrived at its full growth, the larva 
betakes itself to the banks of the water it inhabits, 
and forming itself an oval hollow in the soft earth 
or clay, in a few days changes into a chrysalis 
much resembling that of the genus Scarabgeus, 
and of a whitish colour. From this, in the space 
of about three weeks, proceeds the complete in- 
sect. The male, which has been described above, 
is distinguishable not only by the smoothness of 
the wing-sheaths, but by the far superior breadth of 
the fore-feet, which are expanded near the tips into 
a broad oval dilatation, concave oh the lower sur- 
face : the female, instead of being smooth, has the 
wing-shells marked from about the middle to the 
tips with numerous deeply-impressed longitudinal 
furrows. nt 
Dytiscus cinereus is a much smaller species, 
and of a broader shape in proportion : the male is 
of a blackish olive-colour, with an ochre-coloured 
band across the thorax, which, as well as the 
smooth wing-shells, is edged with ochre-colour, 
while the female has those parts of a dull ash- 
colour, strongly marked by several longitudinal 
furrows. The larva of this species is of the same 
general form with that of the preceding, but pro- 
portionally smaller, and with a longer neck. It 
is not uncommon in stagnant waters. 
