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Show 526 INSECTA. the manner of a snout; where the thorax is not widened from before posteriorly, and does not present the figure of a trape· zium or truncated cone; and where the clytra arc neither very short and squamiform, nor abruptly narrowed a little b~yond t~eir ba.~e. ~nd s~bulate at ~he extremity. The spe· c1es of this subdiVISIOn might be des1gnated by the title of re. gular Cerambyci, in contradistinction to those of the fo1lowing one, which, in many respects, are anomalous, and the last of which seem to be connected with those of the tribe that follows it. They compose the genera Cerarnbyx, Clytus, Callidium of Fabricius, and some of his Stenocori, a different genus from that similarly and previously so named by Geoffroy. They form the genus Cerambyx of Linn reus, to which we must also add some of his Lepturre. Modern entomologists have augmented the number of these generic sections, but their characters are so little distinct, and so much blended, that these genera may ail be united in one, orm CERAMBYX. A number of species, all from South America, proportionally shorter and wider than the following ones, with the antennre frequently pecti· nated, serrated, Ol' spinous, are remarkable for the extent of their tho· rax, the length of which is almost equal to that of the elytra; sometimes glabrous, it is almost semi-orbicular, and nearly unidentated at the posterior angles; at others it is very uneven and tuberculous. Their prresternum is either carinated or terminated in a point, or plane, truncated, entire or emarginated at its posterior· extremity, which is laid on an anterior projection of the mesosternum. Their ante· rior legs, at least, are remote at base. The scutellum is lat·ge in several; the tarsi are short and dilated. Those of this division, in which the thorax, almost semiorbicular and always very large, is smooth or· simply granulous, with a single tooth on each side, at the posterior angles, in which the posterior extremity of the prresternutn is plane and truncated, eithet· unemar· ginated, or marginated and laid on the mesosternum; whet·e the scutellum is always very large, and the legs are very remote, form two subgenet·a, LxssoNoTus, Dalm.-Cerambyx, Fab. Where the antennre are long, strongly compressed, and serrated COLgOPTERA. 527 or pectinated, and whe1·e the posterior extt·enrity of the prresternum offers no emarginati·on( 1 ). • MEGADERus, Dej .-Callidium, Fab. Where the antennre are simple, and shorter than the ho.dy, and the posterior extremity of the prresternum is emarginated, and receives, in that emargination, the opposite end of th"e mesosternum, 50 that they are intimately united Ol' seem to form but one plane(2). Those, in which the thot·ax is very uneven, tuberculous, or pluridentated, with the p1·restcrnum carinated or ter·minated posteriorly in a point, have been arranged ir four subgenera. Here the antennre are long, setaceous and simple, or at most slightly spinous or furnished with fasciculi of hairs. The thorax is always lar·ge, very uneven, and hardly wider than it i's long. DonoAoEnus, Dej.-Cerambyx, Oliv. ( The species of this subgenus are distinguished from all the others by their large vertical head, which is almost as wide as the thorax taken in its greatest transversal diamete1·,and plain and densely pilose before. The autennre are very remote. The prcesternum is not raised into a carina, and terminates simply in a point. T~e scutellum is small(S). TnACJHYDEREs, Dulm.-Cerambyx, Fab. Where the thorax is large, much wider than the head, and the posterior (and ft·equently the opposite) extremity of the prresternum is raised into a carina; where the scutellum is elongated, tl1e elytra are widest at base, and become narrower as they progress towards the extremity; and where the antennre are not furnished with fasciculi of hait·s( 4). LoPIIONooEnus, Lat. Whe1·e the head is also nart·ower than the tho1·ax, and the posteriot · extremity of the prresternum is carinated; but this thorax, as well as the scutellum, is proportionally smaller. The elytra are widened towards their· extremity, or at least do not beco~e nart·ower; (1) See Schrenh., Synon. Insect.; Dalman, Anal. Entom.; and Germar, I~sect. Spec. Nov. ' (2) Callidium stigma, Fab.; Dej., Catal., p. 106. (3) Cerambyx barbatua, Oliv.; Dej., Ibid., p. 105. (4) Schrenherr, Synon. Insect., I, 3, p· 364. |
