12 Dro LzacH's Classification of the Notonectides. 
Fam. I. 
AI the insects of this family swim on their back, moving by 
means of their long hinder legs, which resemble oars; whence 
they have been aptly named boat-flies. 
Gen. 1. NOTONECTA. : 
Besides the characters given in the above table, the following 
will be useful in order to enable the young entomologist to di- 
stinguish this genus from Prza, from which it has not been sepa- 
rated by any entomologist*. 
The thorax is hexagonal, the anterior part is much attenuated, 
and the hinder margin is straight. The head is narrower than 
the broadest part of the thorax; the eyes are oblong, and cón- . 
verge a little behind ; the hinder legs are much ciliated, and the 
claws are so minute as to be discovered with great rent - ; 
the tips of the 'elytra are notched. 
Spec. 1. Notonecta furcata. 
N. elytris nigris, maculis duabus baseos griseis: posticá — 
Notonecta furcata. Fabr. Ent. Syst. iv. 58. 
Syst. Rhyng. 102. 2. 
Oliv. Encycl. Méthod. Hist. Nat. viii. 388. 2. 
Var. £. Elytris maculá ferrugineá. 
Habitat in Caledoniz, Angli: aquis vulgatissime. 
Ogs. Elytra apice fuliginosa; dorsum nigrum. 
Spec. 2. Notonecta maculata. 
N. elytris fusco ferrugineoque variis, dorso ferrugineo fascià 
media pernigrá. ug 
Notonecta maculata. Fabr. Ent. Syst. iv. 58. 
—-— Syst. Rhyng. 103. 4. 
* In the Genera Crustaceorum et Insectorum, tom. iii. p. 150, the accurate Latreille 
has detailed the principal characters of PLEA, which he considered as a species of Notonecta. 
Notonecta 
