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Show 414 INSECTA. AoANTHooERus, Mac Leay. First joint of the antennre very large, dilated superiorly and 1 . . . . arnt. mform; the edges of the mtermedtate leaflet of the club, when it. bent, are exposed. The tibire, the four last particularly, are lamell;~ form and cover the tarsi, folding over them when the leg is co. tracted. ·r he ep.ts toma t~pers to a po.m t or terminates in an anglen. The thorax is almost semllunar( I). There, or in our second division of the Arenicoli-Trogides, Mac Leay-the antennre, scarcely longer than the head, are always com. posed of ten joints, the first of which is large and very hairy. The ligula is entirely concealed by the mentum. The labrum and man. dibles are but little :xpo~ed, a~d the. latter are t~ick. The palpi are short. The menlum 1s entirely pilose. The mner side of the maxillre is armed with teeth. The cinereous or earth-coloured body is very scabrous or tuberculous above. The head is inclined, terminates in an angle or narrows to a point. The thorax is short, transversal, without a .lateral border, sinuous posteriorly, with projecting anterior angles. The abdomen is large, arched, and covered with very hard elytra. The anterior legs advance, and their thighs cover the under part of the head. These Insects produce a stridu· lous noise by the reiterated and alternate rubbing of the pedicle or the mesothorax against the internal parietes of the thoracic cavity. They are found in earth or sand, and appear to gnaw the rootsof vegetables. They form the genus TRox, Fab. Oliv. From which, under the generic name of PaoBERus, M. MacLeay, Jun., has separated those in which the sides of the thorax are depressed, dilated and bordered with spines, and which are destitute of wings. On each side of the posterior edge of the thorax is a deep emargination; the epistoma is rounded anteriorly(2). (1) Mac Leay, lb. p. 136; Jl.. ameus, a species for the knowledge of which lam indebted to one of our most able naval engineers, and not less excellent entomologist, M. Lefebure de Cerisy. M. Mac Leay refers the Troxspinicornu, Fab.,to the same genus. (2) 7tox horridw, Fab ; Mac Leay, Hor. En tom., I, 1, p. 137. The species of Trox, Fab., remain where they are. See this author, Olivier and Schcenherr. The genera Cryptodua and Mt£chidiua, arranged by Mac Leay in his family of the Trogid~ directly after that of Phoberus, have the posterior extremity of the ab· domen exposed, and nine joints in the antennre, characters which appear tort· move them from Trox. I suspect that the .l\lachidii, from the form and emargina· tion of the labrum and from some other characters, are allied to the Melolonthz. COLEOPTERA. 415 .\third section, that of the X YLOPHILI, will comprise the Geotrupes of Fabr~cius, and some of his Cetonire. Here the scutellum is always distmct, and the elyt1·a do not cover the posterior extremity of the abdomen. The tarsial crotchets of several are unequal. The antennre always consist of ten joints, the three last forming a foliaceous club, of which the intermediate leaflet is never completely concealed or encased by the two others. The labt·um is not salient, and its anterior extremity at most is exposed. The mandibles are entirely corneous, and jut out beyond the sides of the head. The maxillre are corneous or of a solid consistence, straight and commonly dentated. The ligula is covered by an ovoid or triangular mentum narrowed and truncated at its extremity, the angles of which are frequently dilated. All the legs are inserted at an equal distance from each other. A first division will comprise the Geotrupes of Fabricius. The males differ from the females in particular projections resembling horns or tubercles on the head or thorax, or on both, and sometimes also in the form of the latter. The epistoma is small, triangular, and either pointed, or truncated and bidentated at the extremity. The labrum is almost entirely concealed. Here, the maxillre terminate in a simple, coriaceous, crustaceous lobe, more or less pilose and without teeth; there, they are entirely squamous, pointed, and present but a small number of teeth, accompanied with hairs. The mentum is ovoid or in the form of a truncated triangle. There is no projection on the pectus. The tarsial crotchets are generally equal. The scutellum is small or moderate. Their colours verge on black or brown. Sometimes the maxillre are terminated by a coriaceous or crustaceous edentated lobe, simply pilose or furnished with spinuliform cilia. 0RYOTEs, lllig.-Scarabreus, Lin. Where the legs differ but little in length, and the four posterior tibire are thick, strongly incised or emarginated, with an extremely wide extremity, which, in several, is as if stellated. 0. nasicornis; S. nasicornis, L:; Rces., II, vi, vii. Fifteen lines in length; of a glossy maronne-brown; point of the epistoma truncated; a conical horn, more or less long, arcuated The Cryptodi are distinguished from all other Scarab~ides by their mentum which almost completely covers the mouth beneath, and even by the labial palpi, situated, u well as the ligula, behind it. These two genera are established on AUIItralian Insects which I have not seen. |
