H E L O P I D /E H E M I P T K it A. 



Unlike the former, the struc- | and very much reticulated, resemblin 



considerable interest. 



tnre of the legs, and the want of cilia\ or hairs, on 

 the limbs, prevents them from swimming ; so that 

 it is rather by walking than swimming that they pre- 

 serve their aquatic situation. The body is oblong 

 and depressed ; the antenna; composed of nine joints 

 clubbed at the tips ; the mandibles are destitute ol 

 teeth ; and the maxillary palpi very long, a character 

 which they possess in common with the more typical 

 water-beetles (Hydroph'didfB} ; they creep but slowly, 

 and may often be observed in muddy water and at 

 the roots of aquatic plants ; sometimes also in fine 

 weather they leave the water and take flight. The 

 genera are Helophorus, Hydrochus, Ochthebius, and Hy- 

 di-fiia, the first of which is distinguished by the mode- 

 rate length of the maxillary palpi, which have the last 

 joint thickened and oval, and by the transverse form 

 of the thorax. There are eight English species, the 

 Silpha aquatica of Linnaeus being the type. It is 

 about a quarter of an inch long, and of a dull brassy 

 brown colour, with the elytra greyish. In Hydrochus 

 the thorax is long and the eyes very prominent, 

 whence the typical species is termed Cicindeloidcs, in 

 allusion to its resemblance in these respects to the 

 tiger beetles. In Hydraina the maxillary palpi are 

 very long, being nearly half the length of the body. 



HELOPID.E (Stephens; HELOPII, Latreille). 

 A very extensive family of coleopterous insects, be- 

 longing to the section Hcteromcra and to the subsection 

 Stenelytra of Latreille ; having the antenna? inserted 

 near the eyes, beneath the lateral margins of the head, 

 nearly filiform, or but slightly thickened at the tips ; 

 the joints generally cylindric and slender at the base, 

 the third joint being elongated ; the tips of the man- 

 dibles have a notch ; the maxillary palpi are terminated 

 by a large hatchet-shaped joint ; the eyes are oblong, 

 and kidney-shaped ; the tarsi generally simple, as 

 well as the claws. These insects, which are gene- 

 rally elegantly marked and variegated in their colours, 

 arc for the most part inhabitants of tropical regions, 

 where vegetation abounds, the perfect insects 

 being chiefly found upon the trunks of old and decay- 

 ing trees ; the larvae, of which very few have been 

 observed, feed also upon the wood of such trees. 

 They are filiform, smooth, and shining, with very 

 short legs, resembling those of the meal-worm (Tcnc- 

 brio mo/itor). Mr. Stephens introduces the Cistelidcs 

 of Latreille into this family, which have the antennae 

 exposed at the base, the mandibles entire at the tips, 

 and the tarsal claws toothed. In other respects they 

 are closely allied to the true Helopida;. There are 

 numerous genera established in this family, chiefly 

 founded upon exotic species, of whose habits nothing 

 is known. The English genera are He/ops, Eryjc, 

 Mycetodiarus, Cislela, and Allecula, which, with the 

 exception of the first, belong to the subdivision of the 

 Cistclidcs. The genus IIclops is remarkable for having 

 the anterior tarsi of the males dilated. The thorax is 

 transverse, and applied to the base of the elytra. 

 There are four British species, of which the type is 

 the He/ops caraboides, an insect found abundantly 

 throughout the kingdom at the roots and under the 

 bark of trees and upon the broom. It is of an elongate 

 ovate form, of a pitchy brown colour, and thickly 

 punctured, the antennae and tarsi being of a dusky red. 

 HEMEROBIID^E (HEMEROBID.E, Leach). A 

 family of neuropterous insects belonging to the sec- 

 tion Pltuiipennes of Latreille, having the body slen- 

 der and much shorter than the wings, which are large 



very fine net- 

 work ; the antenna: slender and filiform ; the palpi 

 only four in number, the terminal joint being thicker 

 than the preceding ; the first segment of the thorax 

 is very small, and the wings, when shut, are deflexed ; 

 the body is soft ; the eyes globular, and often splen- 

 didly metallic. They fly very slowly. These insects, 

 which in their perfect state seem' so delicate and 

 harmless, are produced from grubs which are exceed- 

 ingly ravenous, very much resembling those of the 

 ant-lion (Myrmelmnidce) not only in their appearance 

 but also in their ravenous propensities. Like the 

 grubs of the ladybirds, they subsist upon plant-lice, 

 which they seize with their jaws, which are long and 

 curved, and which they suck to death in a very short 

 time. Some of these larva; moreover invest them- 

 selves with the skins of their victims, which gives 

 them an extraordinary appearance. When full grown 

 the larva envelopes itself in a globular cocoon, com- 

 posed of a very fine tissue of silk, and which in pro- 

 portion to the size of either the larva or perfect 

 fly is very small. The spinnerets of the larva are 

 placed at the extremity of its body, as in those of the 

 ant-lions. These larvae are produced from eggs, depo- 

 sited by the females in patches of ten or a dozen 

 together upon the leaves or stems of various plants, 

 of a white colour, and raised from the leaf upon a 

 long glutinous footstalk of the same colour, finer 

 than a hair. Hence by some authors they have been 

 described as a remarkable species of fungi. From 

 their habits they are thus essentially beneficial from 

 the number of aphides they destroy; and it is a 

 curious circumstance that, like the ladybirds, they 

 should emit a strong and exceedingly disagreeable 

 smell, which remains upon the hand for a consider- 

 able length of time. The genera belonging to this 

 family are Osmylus, Xymplws, from New Holland, 

 Drepaneptcryx, Chrysopa, and Heinerobius. 



In Osmylus, which comprises the largest British 

 species, (O. macidattis, F.) the ocelli are three in 

 number, and the antenna; moniliform. In Chrysopa 

 (Leach) the ocelli are wanting, and the joints of the 

 antennae are cylindric. There are twelve Briti-h 

 species, including the type Heinerobius perla (Linn.), 

 or the golden-eye, a very elegant species, of a green 

 colour, the wings clear, with green veins. It is a very 

 common species. The Hemerobii, as restricted by 

 Dr. Leach, are smaller species, having moniliform 

 ioints to the antennae. 



HEMEROCALLIDEyE. A natural order of plants 

 comprising eighteen genera, and two hundred and sixty- 

 one species already described. They are mostly fine 

 showy plants, bearing their flowers in umbels or ra- 

 cemes, either white, yellow, red, or blue. They are 

 mostly inhabitants of temperate climates, and are of 

 little utility, with the exception of the aloe, the medi- 

 cal and economical uses of which need hardly be 

 mentioned. Here we find some of the gayest orna- 

 ments of the stove, greenhouse, and flower-garde 1 !). 

 The aletris, agapanthus, tritoma, &c. belong to this 

 order, and many other equally interesting plants. 



HEMEROCALLIS (Linnaeus) is the day-lily, a 

 common hardy flower-border plant belonging to 

 Hcjcandria, and is so named from the fugacious cha- 

 racter of its flowers. It gives a title to the natural 

 order HemerocallidecE. 



HEMIPTERA. In the Linmean system of 

 zoology the name of the second order of insects, cha- 

 racterised bv having the wing-covers of a consistence 

 Z Z 2 



