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Show 296 INSECTA. J• oints are much wider, and in this case the succeeding one is alw smaller than its antecedent; somet.i mes t h e latter and the two p~re. ceding ones are larger, almost equal, and in the form of a reversed heart or triangular: the first joints of the four following tarsi ar more slender and elongated, almost cylindrical, or in the form of a: elongated and reversed cone. In some, the hooks of the tarsi are simple or not dentated. Here the third joint of the antennre is, at most, double the length of the preceding one. The feet are generally robust, the thighs thick and more or less oval; the thorax measured in its greatest transversal diameter is as wide as the clytra. Sometimes the mandibles are evidently shorter than the head, not projecting beyond the labrum at most more than half their length. We will begin with those in which the exterior palpi are filiform. ZABRus, Clairv. Bon.-Pelor, Bon. Distinguished from the following by the last joint of the maxillary palpi, which is evidently shorter than the preceding one, and by the two spines which terminate the two anterior tibice( 1 ). PoGoNus, Zieg. Dej. The Pogoni, which in a natural order appear to us to be closely a~ lied to the .llrnarre of Bonelli, are removed from the other Carabiciof this division by the mode of dilatation peculiar to the two anterior tarsi of the males; the two first joints, of which the radical is the largest, are alone dilated; the two following ones are small and equal. Their body is usually more oblong than that of an Amara, separated this insect from the Feronire, and formed the genus CAMPToscnrs. The last joint of the exterior palpi being strongly securiform in Mus, that genus should also be distinguished from the Feronire. Count Dejean has ob~el'ved that in the genus PELon, of Bonelli, the toothofthe middle of the emargination of the mentum is bifid, while it is entire in Zabros. lie retains, as we have already stated, his genus .ll.mara, hut if the characters assigned to it be compared with those of the Feronire, the slightness of this generic distinction will soon be perceived. The last joint of the palpi of the Amar~eis slightly ovo.l; it is cylindrical or slightly securiform in the Feronia:. His genw Tetragonoderua differs but vel'y little from that of Amara. The tooth in the mid· dle of the emargination of the mentum is truncated and entire, or without a fissure. (1) Carabua gibbus, Fab.; Labrus gibbus, Clairv.~ Entom. Helv., II, xi. For the other species see Catalogue, &c. of Dejean, and the thil'd volume of his Speciea, Gener., &c. The apterous species, such as the Blapa spinipes, Fab.; Panz. Faun. Insect. German., XCVI, 2, form the genus Pelor. COLEOPTERA. 297 best'd es w hich they appear to inhabit, exclusively. the co•a st or bor-d sof salt-water ponds(!). e;t is only by an analogous character that we can distinguish from the last the TETRAGONODERus, Dej. Anterior tarsi of the males less dilated, in proportion, than in the following ones, their first joints being more narrow, elongated, and rat he r 1·n the form of a reversed cone than cordiform. These Insects are peculiar to South America(2). ·FERONIA, Lat. Three first joints of the anterior tarsi of the males strongly dilated, in the form of a reversed heart; second and third rather transversal than longitudinal. This subgenus will include the numerous generic sections given in the Catalogue, &c. of Count Dejean, such as .llmara, Pmcilus, .llrgutor, Omaseus, Platysma, Pterostichus, .flbax, Steropus, Percus, Molops, Cophoaus. This learned entomologist has since-Species IIIperceived the impossibility. of distinguishing ~hem! the first excepted, which he still retams; the others he umtes m one great generic section which he calls, with me, Feronia. But even as regards the Amarre themselves, I have vainly sought for characters in the autennre and parts of the mouth, which might clearly distinguish them from the other genera. The one drawn from the tooth of the middle of the emargination of the mentum, tg say nothing of the slight degree of importance attached to it, is very equivocal; this tooth in all these Carabici appears to me to be emarginated at the extremity, though somewhat more deeply or distinctly in some than in others. The antennre of several are slightly granose, or composed of joints comparatively shorter, and rounded at the summit; but the limits of this distinction cannot be rigorously defined. I say the same of the concavity of the anterior margin of the labrum and of the form of the thorax. The Feronire may form three divisions: I. Those species, generally furnished with wings, in · which ~he more or less oval body is slightly convex or arcuated above, wtth more filiform antennre, the head proportionably narrower, and the (1) See the Catalogue of DeJ·ean. Germar in the Fauna Iusectorum Europre has figured two species: Pogmus halophilu&, X, i; Harpa l ua lu rz' dt'p tnnt.l , VIII• 2' allied to the Pogonua pallidipennis of the first: (2) Harpalu1 circumfuaua, Germ. Insect. Spec. Nov. I, 26? VoL. III.-2 N |
