H1IYNC0TA. 
29 
Underneath the prettily-marked wing-cases of the 
boatman you may see, by examination, a pair of large 
hyaline wings which the possessor uses when so inclined. 
Though when sunning itself on the surface of the 
water, Notonecta generally lies on his back, he can 
swim equally well with the keel up, and first turns on 
one side then on another with great rapidity. The 
larva and pupa resemble the imago, except that the 
former has not a vestige of wings, and the latter has 
rudimentary ones. The boatman's length is from 7 to 
8 lines. There are other genera allied to Notonecta , as 
Plea , Corixa , Cjjmatia , and Sigara , all of which are 
good swimmers. Of Plea there is only one British 
species, viz., P. minutissima, which is not much above 
a line in length ; it is common in stagnant waters. Of 
the other genera, Corixa Geoffroyi , about 5 lines long, 
is extremely common in stagnant waters ; its form 
must be more or less familiar to every one who has 
stood on a bank and watched the fishing-net hauled in, 
when hundreds of these little smoky-black insects are 
jumping about in every direction, as not knowing what 
has happened to them. To the right of the boatman 
will be seen a curious scorpion-like creature (Fig. 11) 
with its fore-legs extended pincer-like, in a threatening 
attitude ; this is the Nepa Cinerea or Water-Scorpion, 
which I have taken to illustrate the family of Nepida ?. 
This insect is a dull dingy-looking creature with a small 
pointed head, scorpion-like fore-legs, and a tail with two 
long bristle-like projections; it is nearly an inch long, 
not including the tail. It is painfully sluggish in its 
movements, and on watching it one is impatiently 
prompted to say with the policeman, “ Move on—Move 
