4.58 MODERN CLASSIFICATION OF INSECTS. 
The species of the first family, NoronecTIp#&*, are distinguished by 
their pre-eminently natatorial habits, their hind pair of legs being greatly 
elongated and strongly ciliated, forming a pair of oars (generally without 
ungues), whence these insects have obtained the name of boat-flies 
(jig. 119. 1. Notonecta furcata): Their general form is also much 
Fig. 119. 


better fitted for swimming than any of the rest, being more boat- 
shaped, with the head nearly as wide as any other part of the body: 
although they prey upon other insects, the fore legs are not raptorial, 
being simply incurved, the anterior tarsi being two-jointed, and termi- 
nated by two ungues (fig. 119. 8.); the middle legs are also similarly 
formed to the anterior pair, except that the femora are furnished be- 
neath at the base, in Notonecta, with a pencil of hairs, and near the 
apex with a short spine, which I have not seen noticed by authors. The 
elytra are generally deflexed at the sides ; the eyes are very large, and 
bi-emarginate behind (fig. 119. 2.) ; the antenne (fig. 119.7.) inserted 
behind and beneath the eyes, 4-jointed, the basal joint inserted at its 
side, the others diminishing in size. The rostrum (fig. 119. 2. and 4.) 
is short, thick, and apparently only 3-jointed; with this instrument 
they are enabled to inflict a painful wound, thrusting its extremity into 
the flesh, into which they also introduce their setaceous maxille and 

* Bistiocr. Rerer. To THE NoToNECcTIDA. 
Sahlberg. Observ. qued. Histor. Notonect. imprimis Fennicarum illustrantes. 
Abo, 4to. 1819. 
Leach. On the Classif. of the Notonectide, Linn. Trans. vol. xii. 
Fallen. "ydrocorides et Naucorides Suecia, Lund. 1814. 8vo. 
Spinola, Essai sur es Hémipt. 
And the other general works on the order. 
