12 Dr. Leach's Classification of the Notonectides. 



Fam. I. 

 All 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 hoat-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 Plea, 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 con- 

 A'erge a little behind ; the hinder legs are much ciliated, and the 

 claws are so minute as to be discovered with great difficulty; 

 the tips of the elytra are notched. 



Spec. 1. Notonecia furcata. 

 N. elytris nigris, maculis duabus baseos griseis : postic^ majore. 

 Notonecta furcata. Fabr. Ent. Si/st. iv. 58. 



Syst. Rhyng. 102. 2. 



Oliv. Enci/cl. Mithod. Hist. JSat. viii. 388. 2. 

 Var. jS. Elytris macula ferrugined. 

 Habitat in Caledoniee, Angliae aquis vulgatissime. 

 Obs. Elytra apice fuliginosa ; dorsum nigrum. 



Spec. 2. Notonecta maculata. 

 N. elytris fusco ferrugineoque variis, dorso ferrugineo fasci4 



medi^ pernigrA. 

 Notonecta maculata. Fabr. Ent. Syst. iv. 58. 



Syst. RInjng. 103. 4. 



* In the Genera Crustaceorum et Insectorum, torn. iii. p. 150, the accurate Latreille 

 ha* detailed the principal characters of Plea, which he considered as a species of Notonecta. 



Notonecta 



