IIEMIPTERA. 563 



nutritive fluid, successively compressed, is forced u]) tlie main caual, and arrives at tlie ceso- 

 pliagus ; the slieath of the sucker is often elbowed, or forms an angle. Like other sucking 

 insects, the Ilemiptera possess salivary vessels. 



In tlie majority of the insects of this order the Aving-covers are coriaceous, or crustaceous, 

 with the posterior extremity membranous, and forming, as it Avere, a kind of supplemental 

 piece ; they nearly always cross each other : those of other Hemiptera are merely thicker and 

 larger than the hind wings, scrai-membranous, like the wing-covers of the Orthoptera, and 

 sometimes opaque and coloured, sometimes transparent and veined. The wings have several 

 longitudinal folds. 



The composition of the thorax begins to exhibit the modifications which we meet with in 

 the following orders. Its anterior segment, hitherto known under the name of corselet 

 [thorax, or more strictly, prothorax], is in many of much less extent, and is incorporated with 

 the secoud, which is equally exposed. 



Many possess ocelli, but their number is generally only tvco. 



The liemi])tera [like the Orthoptera] exhibit to us, in their tluee states, the same forms 

 and habits. The only change they undergo consists in the developement of wings, and an 

 increase in the size of the body. 



I divide the order into two sections \Heferoptera and Homoptera, regarded as distinct 

 orders by many English authors, under the names of Hemiptera and Homoptera^. 



In the hrst section, Heteroptera, the rostrum arises from the front of the head, the wing- 

 cases are membranous at the extremity, and the first segment of the thorax is much longer 

 than the others, and forms by itself the corselet. 



The wing-covers and wings are always horizontal, or slightly inclined. 



This section is composed of two families [_Geocori:^a; and Hydrocorlsaf]. The first, 



Geocoris.'E (or Land-bugs), — ■ 



Have ttie antenna; exposed, longer than the liead, and inserted between the eyes, near dieir inner 



marf(iu ; the lavsi have [generally] three joints, the first of which is often very short. They form 



tne gcnns 



CiMEX, Linn., — 



Some of which, Lonr/ilahres, have the sheath of the snckcr composed of four distinct and exposed 



joints ; the upper lip is considerably prolonged beyond the head, like an awl, and transversely striated 



on the upper side ; tlie tarsi have always three distinct joints, the first equal in length to, or longer 



than the second. These species emit, in general, a Ntry disagreeable scent, and sack other insects. 



Sometimes the antenna?, always filiform, are composed of five joints ; the body is generally short, oval, 



or rounded. 



ScuTELLERA, Lam., — 



In which the scutelluni covers the abdomen. Cimex I'meatus, Linn, [a reputed British insect]. 



Penta/oma, OUv., in which the scutellum covers only a portion of the upper-side of the abdomen. This genus, 



as proposed by Ohvier, comprises five others in the iSysiemn RJuingotorum of Fabricius; but his 



g;ronps are imperfectly characterized and badly arrang-ed. His o;enera ^^lia a.ndHah/s are Pen- 



tatOTiin*, which have tlie head more prolong^ed, and advanced in front like a snout, more or less 



triaTii^-iiIar. The type of the former is ^lia acuminata [a rare British species], which differs 



from the rest in having the antennse covered at the base by the anterior and detached marg^iu 



of the under-.side of the thorax, and by the scutellum of much larc:;er size, \vhereby this species 



more nearly approaches Scutellera. His g^enus Ci/dnus has the head seen from above, broad, 



semicircular; the tliorax transversely square, scarcely narrower in front than behind, and the 



tibiae are often spinose. These species are found on the g;round ; some other species may also 



be united, which have the sternum neither keeled nor spined : such are Cimex ornaius and 



olaraccus, [hantlsonie rare British species, forming Hahn's genus Euri/dema], 



Other Pcntatomae, having the mesosternum elevated in the manner of a keel, or exhibiting a point like a spine, 



are generically distinguished under the name of Edesxa^ employed by Fabricius. Many of the species which he 



introduces into this genus possess this character, which is also found in some of his species of Cimex, as P. hce- 



viorr/ioida/'.';, Linn, [tlie type of Curtis's genus Acaitthosoma, and P. griscus, the type of Laporte's genus 



I\aph''j<i.slcv^. 



o o 2 



