226 MODERN SYSTEM. 



• Fam. VII. NoTONECTiD.f:. Leach. 

 " Linne and all his predecessors comprehended the species under 

 the generic appellation Notonecta. The accurate Geoffroy was the 

 first who separated Notonecta into two genera, which have been 

 adopted by most succeeding \vriters, excepting Linne, who in his 

 last edition of the Si/stema Natura has merely given the synonyn« 

 of that author, without taking the least notice of the important cha- 

 racters which induced him to separate them." 



De Geer confounded the animals of this tribe with Nepa and Nait- 

 coris, whilst Latreille and Olivier placed them in a division of their 

 family Hydrocorisa. In the Edinburgh Encyclopedia Dr. Leach se- 

 parated them from the Hydrocorisc, and placed them in a particular 

 tribe, named in that work Notoneclidcs, and in the twelfth volume of 

 the Transactions of the Linnean Society he has given an excellent pa- 

 per, in which are described at large the whole of the British species 

 hitherto discovered, which consist of four very natural genera. 

 Stirps 1. — Body cylindrical oval, or nearly square : tarsi with t\vo arti- 

 culations. {Scutellum large) 



"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 boat-flies." 



Gemis 289. NOTONECTA of authors. 



Body oval and cylindric : antenna with the third articulation slenderer 

 than the second: anterior tarsi with the first articulation long: clazts 

 of the hinder feet very minute. 



Besides the above characters, tlie following will be useful, in order 

 to enable the young entomologist to distinguish this genus from 

 Plea, from wliich it was first separated by that close exammer of 

 nature Dr. Leach. 



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 converge a lit- 

 tle behind: the hinder legs are much ciliated, and the dares are so mi- 

 nute as to be discovered with great difficvdty : the tips of the elytra 

 are notched. 



Sp. 1. Not. f areata. Elytra black, with two grayish spots at the base, 

 and two larger ones at the posterior part. 



Notonecta furcata. Fabr., OUv., Leach. 



Var. /3. Elytra with ferrugineous spots. 



Inhabits ponds and ditches in England and Scotland. 



Sp. 2. Not. maculata. Elytra dark brown and varied with spats : baclp 



ferrugineous with a darker fascia. 

 Notonecta maculata. OUv.j Leach. Notonecta glauca. Var, p. Latr. 



