HEMIPTERA. 563 



nutritive fluid, successively compressed, is forced up the main canal, and arrives at the oeso- 

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

 insects, the Ilemiptera possess salivary vessels. 



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

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

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

 larger than the hind wings, serai-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 second, which is equally exposed. 



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



The Ilerniptera [like the Orthoptera] exhibit to us, in their three states, the same forms 

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

 increase in the size of the body. 



I divide the order into two sections [Heteroptera and Homoptera, regarded as distinct 

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



In the first 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 [Geocorisce and Hydrocorisce]. The first, 



Geocoris.-e (or Land-bugs), — 

 Have the antenna? exposed, longer than the head, and inserted between the eyes, near their inner 

 margin ; the tarsi have [generally] three joints, the first of which is often very short. They form 

 tne genus 



Cimex, Linn., — 



Some of which, Lonr/ilabres, have the sheath of the sucker 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 ; the tarsi have always three distinct joints, the first equal in length to, or longer 



than the second. These species emit, in general, a very disagreeable scent, and suck 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. Oimex Hneahu, Linn, [a reputed British insect]. 

 Pentatoma, Oliv., in which the scutellum covers only a portion of the upper-side of the abdomen. This gems, 

 as proposed by Olivier, comprises five others in the Sgtttma Hhyngotorum of Fahricius; but his 

 groups are imperfectly characterized and badly arranged. His genera .l'.H« and Bafy* are Pen- 

 tatome, which have the head more prolonged, and advanced in front like a snout, more or leas 

 triangular. The type of the former is .h'A'ia muminala [a ran' British spi ri. •> , » lu< h differs 

 from the rest in having the antennas covered at the baaebj the anterior and detached margin 

 or the under-side of the thorax, and by the scutelluni of ranch larger sue, whereby this q 

 more nearly approaches Seutollera. His genus Ojfdmu has the head seen from above, broad, 

 semicircular j the thorax transversely square, scarcely narrower in front than behind, and the 



tibia an Often spinose. These species are found on the ground ; some Other species DM) altO 



BMcSam!™** '"' "Oit^j which have the sternum neither keeled nor spined: such are CtmtM onuttut and 



oloraceut, handsome rare British Bpecies, Forming Halm's genua Bmydema . 



Other Pentatoma-, having the mesoatermim elevated in the manner of a heel, or exhibiting a point like a spine, 



arc gcncrically distinguished under the name of BrffMO, employed bj l'abin ins. Many of the Species which, he 



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



morrhoidalU, Linn, [the type of Curtis'a genus Aeantkonma, and P. griteui, the type of Laporte's genus 



Raphigatter}. 



o o 2 



