abdomen is terminated by a long slender tube; in Monophlebus the ♂ antennæ are very long, multi-articulate, and verticillate, and the abdominal segments furnished with long flattened filaments; whilst in Dorthesia (Cionops Leach) the antennæ & are very long, but simple, and the abdomen terminated by a thick pencil of very delicate white setæ (frontispiece, Vol. I. fig. 8.), and the female (fig. 118. 20. D. cataphractus Sh.) is covered with elongated flakes of a waxy secretion, which in some exotic species in my collection are nearly an inch long. The females in this genus, as well as in Monophlebus, remain active, with the antennæ and legs distinct. Some of the exotic species are of very large size. I possess several males belonging to the genera Monophlebus and Dorthesia *, the wings of which are nearly an inch in expanse, and a gigantic female from New Holland, given to me by Mr. Hope, which has much the appearance and size of the full-grown larva of Estrus Bovis. ORDER HETEROPTERA.† (HEMIPTERA MacLeay, Stephens; HEMIPTERA HETEROPTERA Latr.; HEMIMEROPTERA p. Clairv.; RHYNGOTA p. Fabr.; RHYNCHOTA p. Burm.; ARTHITIGNATHES p. Spin. Essai Hem. Het. p. 20.) CHAR. Wings four; anterior pair larger than the posterior, lapping partly over each other; basal portion coriaceous, apical part membranous. * I cannot agree with M. Dufour in considering Dorthesia as belonging to a family distinct from Coccus. (See his Rech. Anatom. sur les Hémipt. G. 31.) The males even of my gigantic species are entirely destitute of a mouth; and the nervures of the wings as well as many other characters, and especially the possession of only a pair of wings with halteres, agree with the rest of the Coccida. The numerous observations and drawings which I have made in illustration of this family (which has engaged much of my attention) will form the subject of separate memoirs. BIBLIOGR. REFER. TO THE HETEROPTERA. Stoll. Représentation des Punaises, 4to. 49 col. pl. Amsterd. 1788. Modeer, in Vetensk. Acad. Handling. 1764, b. 26. (on Cimices). - Ditto, band 29. (Ditto.) Body depressed. Antennæ generally elongated, filiform. Mouth arising from the anterior and inferior part of the head; promuscidate. Pupa active, semicomplete (Metamorphosis semicomplete Fab.). Having, in the general observations upon the Homoptera, entered into the question of the rank of that and the present group, I shall here merely notice the peculiarities of structure exhibited by these Wolff. Icones Cimicum. Erlang. 1801-4. 4to. pl. 20. Fabricius. Systema Rhyngotorum, 8vo. Bruns. 1801. Ed. Alt. 1803. Fallen. Monogr. Cimicum Sueciæ, in Vetensk. Acad. Handl. 1805-7. and 4to. 1814. Hemipt. Sueciæ, Lund. 1826, 8vo. Ditto, L. Dufour. Recherches Anat. et Physiol. sur les Hémipt. Paris, 4to. (Extr. from Mém. Sav. Etrang. tom. iv.) 1833. Ditto, in Annal. Soc. Ent. France, tom. ii. and tom. iii. - Ditto, in Ann. Sci. Nat. April, 1831. Laporte. Essai d'une Classification Systémat. de l'Ordre des Hémipt., in Guérin's Mag. Zool. 1833. Schellenberg. Die Land und Wasserwanzen. Zurich, 8vo. 1800. H. Schäffer. Nomenclator Entomologicus, 12mo. Regensburg, 1835. Hahn. Icones ad Monographiam Cimicum, fasc. i. 12mo. Nurimb. 1825.-Ditto, die Wanzenartigen Insecten, in Nos. 1831-9. (continued by H. Schäffer). Sm. 8vo. Say. Hemipt. of Rocky Mountains, in Journ. Acad. Philadelph. tom. iv. Ditto, Descript. of new Heteropt. Hemipt. of N. Amer. 8vo. 1831. New Harmony. Thunberg. Dissert. de Hemipt. rostratis Capensibus, 4to. Upsal, 1822. (in 4 parts). Ditto, in Nov. Act. Phys. Nat. Curios. vol. xvi. - Ditto, in Revue Entomol. de Silbermann, tom. ii. Waltl. Reise nach Spanien. Westwood, in Ann. Soc. Ent. de France, tom. iii. 1834. Eversmann, in Bull. Mosc. 1837. Spinola. Essai sur les Hémiptères, 8vo. Gènes, 1837. Cuvierr. Nov. 1839 (2 n. g.). Audouin and Brullé. Hist. Nat. Ins. tom. ix. And the general works of Klug (Symb. Physicæ), Griffith (An. K.), Serville (Encycl. Méth.), Perty (Delect. An. art. Braz.) Pulisot-Beauvois, Donovan, Drury, Coquebert, Curtis, Zetterstedt, Guérin, Boisduval, &c. insects. The head is generally advanced and broad; the eyes generally placed at the sides of the head, which enter the frontal cavity of the prothorax; the ocelli are occasionally present, and two in number; the antennæ are ordinarily of moderate length, and composed of four or five joints; they are mostly filiform, but sometimes have the last joint either thickened or very slender. In the aquatic species (where porrected antennæ would be inconvenient) we find these organs greatly reduced in size, and received into cavities on the underside of the head. The mouth is of the promuscidate construction (see fig. 119. and 122.); the labium or canal being occasionally greatly elongated, extending beneath the body, and either 3- or 4-jointed. The four internal delicate setæ represent the mandibles and maxillæ ; the maxillary and labial palpi are obsolete; the labrum is distinct, triangular, and more or less elongated, closing upon the upper side of the labium at the base, when the setæ enter the labial canal. Savigny has discovered also a minute elongate tongue, trifid in front, between the base of the mandibles and maxillæ, terminated behind by the pharynx in Nepa. In many species which prey upon other insects, as well as in such as reside beneath the bark of trees, the promuscis is very short. The body is ordinarily rounded, oval, or more elongate and depressed. The prothorax is greatly developed (although it never covers the scutellum and wings), imitating in this respect, as well as in the great development of the mesothoracic scutellum, the order Coleoptera: the metathorax is of small extent; on its under side it is furnished with two pores, which secrete the fluid which gives to these insects so unpleasant a scent. The wings, when at rest, are carried horizontally upon the back, the membranous apex of one fore wing lying upon and crossing the same part of the other; the anal area of the fore wings is narrow; the basal part or corium of this pair of wings is often very thick, but occasionally it is sufficiently transparent to permit the nerves with which it is furnished to be perceived; these nerves, both in the corium and apical membrane, vary considerably in number and position in the different * In Hammatocerus, a genus of Brazilian Reduvii, the second joint is composed of a great number of minute articulations. + The mode of insertion of the joints of the rostrum or labium necessarily influences the mode of action of this organ. (See Spinola's Essai, p. 26-.) Savigny first discovered two minute oval pieces attached to the third joint of the labium on the upper side in Nepa, and which he considers as the labial palpi, observing that if the sides of the labium were not turned up, these palpi would be at the under side of the joint, as in the Orthoptera. (Mém. An. Articul. pl. 4. f. 3.) genera. The fore wings rise wide apart at the base, in order to leave space for the large scutellum, which is generally triangular, but sometimes so greatly enlarged as to cover the whole of the upper side of the abdomen, leaving only the lateral margins of the fore wings visible. The feet vary considerably in form; in the majority, however, they are simple, and formed for walking; the anterior pair in some is transformed into a pair of organs of prehension, whilst the hind feet in others are greatly dilated and toothed; these limbs are modified in the aquatic species, to fit them for their functions. The tarsi are short, and never composed of more than three joints. The structure of the mouth of these insects indicates at once that their nutriment consists solely of the juices of plants or animals, which are pumped up the labial canal by the gradual contraction of that organ, the substance from which such juices are derived having been previously wounded by the four sharp internal setæ. By far the greater proportion of these animals are found upon plants from which they derive their nutriment; some, however, feed upon other and weaker insects, found in similar situations. Such are their habits in all their stages, as they continue active, and require food throughout their whole existence. The larvæ are distinguished by the total want of any appearance of the rudiments of wings; whilst, in the pupa, these limbs are to be observed upon the back of the meso- and meta-thorax. The ocelli are only developed in the imago state. The number of species of this order is very great; the majority, however, are found in tropical countries, in which they are mostly ornamented with a great variety of beautiful colours and markings, often vying in splendour with the most splendid of the beetle tribes. The aquatic species, on the other hand, are uniformly of an obscure black or brown colour. They rarely exceed an inch in length, whilst many are not above a line long: they are, for the most part, found in the winged state at the end of the summer. Almost every terrestrial species in the order emits, on being suddenly alarmed or touched, a peculiar odour, more or less disgusting, and which is so well known in the common bed-bug; but which, in some few species (as in Lygæus Pastinacia), assumes a more grateful scent, probably resulting from the nature of the plant on the juices of which it subsists. Others emit the odour of acetic ether, or exhalations similar to that of the majority of the Carabida. Fruit, such as raspberries, &c., is occasionally rendered very offensive to the taste by some of the garden species having previously passed over or sucked its juices. Some species, however, are destitute of this means of defence, and these are chiefly found amongst the predaceous species, with a short curved rostrum. The exhalation of this scent is not, however, continual; for, as Dufour observes, when one of these insects is observed without its being disturbed, no scept is perceived; and if, when suddenly seized, it be plunged into a fluid, innumerable minute bubbles will be observed to issue from two pores between the hind feet, which, on bursting at the surface, immediately emit the scent peculiar to the species. The species of Reduvii, and other carnivorous species, with strong curved beaks, are able to produce, when alarmed, a smart pain, by plunging their rostrum into the flesh, and emitting a drop of fluid discharged from their salivary glands. Others, at the same time, make a creaking noise, by the friction of the fore part of the metathorax within the hollowed base of the prothorax. A peculiarity occurs in some of these insects, whereof analogous instances have already been noticed among the Orthoptera, Homo. ptera, Aphidæ, and even in a species of Chalcididæ, namely, the undeveloped state of some specimens in the imago state which are nevertheless as capable of reproduction as others of the same species which have acquired fully developed wings. Thus the bed-bug has never been observed but with the minute rudimental upper wings, somewhat resembling the ordinary wing-cases of pupae; others, again, as the species of Gerris, Hydrometra, and Velia, are mostly found perfectly apterous, whilst occasionally they are found with full-sized wings. The winged males of Capsus ambulans are stated by Fallen (Monogr. Cim. Suec. p. 6.) to be always found coupled with apterous females. Chorosoma miriformis, Prostemma guttula, Pachymerus brevipennis, &c., are generally found with very short wing-covers, but occasionally with full-sized wings. Two erroneous opinions have been entertained with respect to these undeveloped individuals: first, that they are pupa, and, consequently, that pupae are able to reproduce; and second, that they belong to distinct species. Against the first of these opinions, I will only observe that the structure of the real pupa of such specimens as subsequently attain wings is quite different from that of these imperfect perfect insects, as they may be called; and, against the second, I will refer to the analogy offered by the other groups above alluded to, and to the constant discovery of the winged and imperfect individuals in |