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Show 54() 11\"!-JBCTA. precec1 .m g o nPs·, and nearly fl>rms a truncated ovoid, and whet·c the thorax is at least as long as it is widr( l )· r S.A.MM<ECU S, Bou(liet· ' -.!lnthicus, Fab.-Latridiu.v, Dej. Whel'e t 11 e an t c nll ....,..., , comnt' osed of shot·t and crowded joints, gra· clua 11 y en 1a t• g e, a nd where the maxillary palp. i a.r c abt·upt.ly. termi· nated b y a stou t t t.l· angular club. The thorax 1s w. tder tha.n lt ts long. The botI y 1· s mot·e depressed than in the .p recedtng spectes, the an· tenncc at·c shorter and the eyes less pronnnent(2). The second tribe, or that of the 0RIOCER1 DEs, is distin. guh:hed from the preceding by the mandi,bles, the extremity of which is truncated or presents two ot· three .teeth, and by the ligula, which is entire or hut slightly emargmated. It is composed of the genus CniOCERis, Geoff..-Chrysomela, Lin. Which we will divide as follows: Sometimes the mandibles taper to a point and present two or three teeth at that extremity. The palpi are ~liform. The. antennce, or an or dm. ary th'1 c kness , are almost gt·anose 111 some, and, 111 others. are mostly composed of obconical joints, or such as are evtdently thtcker at their superior extremity. DoNAOIA, Fab.-Leptura, Lin. Where the posterior thighs are large and inflated; the antennre are of equal thickness throughout and their ~o.ints are elongated; the eyes are entire, and the last joint of the tarsL IS enclosed for most of its length between the lobes of the preceding one. These Insects are frequently ornamented with brilliant colours, bronzed or gilded. Several are likewise covered with an extremely fine and silky down, which may prove useful to them when they happen to fall into water, as they live on aquatic pl~nts su.ch as the Iris, Sagittaria, Nymphrea, &c., to which they chng w1th gre~t tenacity. Their larvce live in the roots of the same plants .. Thw chrysalides, accort.ling to the observations of M. ~· Brongmart, are attached to their filaments by one edge only, formmg knots or ~ulbs. The anatomical researches of M. Leon Dufour have induced h1m to (J) See Lat., Gener. Crust. et Insect., lll, p. 45, and I, xi, 5; Oliv., Col., VI, 98, his, and Gyll., Insect. Suec. III, 642. . 'tation. (2) .flnthicu& 2-punctatus, I<'ab.; I place this genus here wtth some hest COLIWP'I'EHA. 547 think that the Donacire should form a particular family. Their hepatic vessels, in number, arrangement, form and structure, constitute a very remarkable exception to those of the Tctramera, and one which even appears to be peculiar to these Insects. These vessels only open into the chylific ventricle, while in all the other Tetramera dissected by this able anatomist, they have two insertions, one vcntriculat · and the other crecal. These biliary ducts, only four in numbe1·, are of two different kinds; those of the first at·e capillary, disposed in two strongly flexed curves, and are inserted oy four distinct ends into a short obround vesicle, situated at the inferior and somewhat lateral extremity of the chylific ventricle; the others, much shorter, thicker, more dilatable, thin and tapering at both ends, have one extt·emity free, and are separately insertetl by the other into the superior and dorsal region of that organ. The whitish pulp contained in them is conside1·ed by M. Dufour as alimentary matter. The esophagus is capillary and without any dilatation in the form of a crop. The chylific ventricle is roughened with very salient papillro. The testes arc very similar to those of the Lepturce. The Iarvre are naked and concealed, as well as those of the last Longi· coJ'Des, an observation which s'trengthens ·the conjectures of M. Dufour. HJEMONIA, Meg. Dej. The Hremonice are Donacice in which the penultimate joint of the tarsi is very small, in the form of a knot, almost entire; the last is very long( I). The PETAURISTEs, Lat. United by Fabricius with the Lemce or our Crioceres properly so called, also have very stout posterior thighs; but the eyes are emarginated; the antennre, as in the latter, arc generally composed of shorter joints, and the lobes of the penultimate joint of the tarsi are much less elongated and merely clasp the root of the following one(2). CRiooERxs, Geoff. Oliv.-Lema, Fab.-Ghr1JBOmela, Lin. Or Crioceres properly so called, are removed from the preceding by this charactet·: their posterior legs are similar to the others, or differ from them but very slightly; the antennce become somewhat and gradually enlarged towards the extl·emity, and arc almost gra· ----~---- (1) The D. equiseti, zosleraJ, Fa.b. (2) The Lema varia, posticata, Fab. |