CLASS V. INSECT A. ,227 



Inhabits England, near Bristol, Plymouth, and Exeter. 

 Elytra with the apex of a palish black. 



Sp. 3. Not. glcntca. Elytra grayish, the margin with minute blackish 



spots : back black, the apex pale brownish. (P/. 5. Jig. 3.) 

 Notonecta glauca of authors. 

 Inhabits Britain in almost every pond. 



Genus 290. PLEA. Leach, Trans, of Linn. Soc. vol. xii. 



Body of a squarish oval : antennte with the third and remainder of the 

 joints largest: anterior tarsivtWh the articulations nearly equal: daws 

 on the hinder feet large. 



The thorax is obscurely hexagonal with the hinder margin prominent 

 and rounded, the head as broad as the broadest part of the thorax : 

 the eyes are rather oblong, without the least tendency to converge 

 behind: the hinder pair of legs not more ciliated than the others, but 

 are terminated by very strong and distinct claws : tips of the elytra 

 acuminated and entire. 



Sp. 1. Not.mimitissima. Gray with a bro^^•nish line in the front: thorax 

 and elytra deeply pimctured. 



Notonecta cinerea, anelytra. Geoff". Jus. Par. i. 477. 2. Notonecta 

 minutissima. Fourc., Latr., Oliv., Fabr. Plea minutissima. Leach. 



Length of the body 1-^ lin. 



Inhabits ponds and stagnant waters near London in profusion. 



" This species has been considered by Geoffroy, Fabricius and Oli- 

 vier, as Notonecta )ninutiiiiiima of Linne, which reference undoubt- 

 edly belongs to the following species; viz. to Sigaru minutixsima." 



" GeoflVoy has described tlie larvae, never having seen the perfect 

 insect." 



Stirps 2. — Body roundish and depressed : tarsi, the anterior with one 

 articulation ; the hinder with two ; base and margin of the elytra 

 only channelled. 



Genus 291. SIGARA. Leach, Trans. Linn. Soc. vol. xii. 

 Scutcllum distinct : thorax divided by a transverse line : body ovate, the 



posterior part acuminated. 

 Sp. 1. Sig. minutissima. Above cinereous: elytra brownish with very 



faint spots; the under part and feet yellowish. 

 Notonecta minutissima. Linne. Sigara minutissima. Leach. 

 Inhabits rivers and running waters in England, Ireland, and Scotland. 

 Length of the body 1 lin. 



Genus 292, CORIXA. Geoffroy, Leach. 

 Scutellum none : thorax transverse, the posterior part produced : body 

 long, the anterior and posterior part rounded. 



*' The thorax is more or less produced behind in all the species of 

 this genus, but is not evident in the first division of this genus until 



p 2 



