OCR Text |
Show 430 INSECTA. outer or terminal one coriaceous. The thorax is oblong, and the posterior legs large( 1 ). AMPHIOOMA, Lat. Outer side of the mandibles rounded and arcuated, the inner not dentated; antenna! club globular; abdomen soft, and all the legs of the ordinary size. The epistoma is strongly bordered. The anterior tibi::e have three teeth exteriorly. The fout· fit·st joints of the tarsi are strongly ci!i. ated in the males. In this and the following subgenus, the maxillre terminate in a membranous, narrow, elongated, thong-like lobe. Their palpi are hardly longer than the others, and the length of their last joint is scarcely greater than that of the preceding one(2). In those, such as ANTH!PNA, Escholtz, The antennal club is formed of free and oval leaflets. The episterna is not bordered before; the median portion of the head forms with it a plate of a long square figure, bordered laterally and posteriorly. The outer side of the anterior tibire has two teeth. The four first joints of the tarsi are dilated and dentiform in the males. These Insects otherwise resemble the Amphicomre(3). In the others, the labrum and mandibles are covered or non-salient, and some at least of their tarsial hooks are bifid. The mentum is elongated and pilose. Sometimes there are two hooks to all the tarsi. The antennre never have more than nine joints. The epistoma is usually trans· versaJ. The palpi are but slightly elongated, and their last jointis oval. Here, the posterior legs differ but little from the others. CHASMOPTERus, Dej.-Melolontha, Illig. All the hooks of the tarsi bifid; terminal lobe of the maxillre nar· row, elongated, with two remote teeth on the inner margin; the body almost oval, thorax rounded and the elytra of equal width th1·ough· -out( 4). (1) Lat., Gen. Crust. et Insect., II, p. 117. (2) See Lat., Gener. Crust. et Insect., II, p. 118; genus .Bmplticoma, first division. (3) .Bmphicoma abdominalia, Lat., Gener. Crust. et Insect., II, p. 119; M. al· pina, Oliv., Col., I, 5, x, 112. (4) See Catalogue, &c., Dej., p. 60. COLEOPTERA. 431 CHASME, Lepel. and Serv. The Chasmes only seem to differ from the preceding Insects in the hooks of the two postet·ior tarsi, the largest of which is alone bifid( I). There, the posterior thighs, at least in the males, are very large and dentated, their tibire thick and terminated by a strong hook. DxoHELES, Lepel. and Serv.-Melolontha, Fab. Oliv. The body is short, but slightly pilose, and the elytra are narrowed towards the extremity, forming an elongated triangle. The posterior legs are partly contractile. All the hooks of the tarsi are equal and bifid. The terminal lobe of the maxillre is dentated along its inner margin, as in Hoplia, to which this subgenus closely approaches( 2 ). Sometimes the two posterior tarsi have but a single hook-those of the others are unequal and bifid. Some, like the preceding, have but nine joints in the antennc:e. LEPITRIX, Lepel. and Serv.-Trichius, Melolontha, Fab. The body short; thorax narrower than the abdomen, nearly square, and slightly narrowed posteriorly; abdomen broad and posterior legs large; last joint of the maxillary palpi much longer than in the preceding subgenera; terminal lobe of the maxillre very small and in the form of a short triangle(S). The others have ten joints in their antennc:e. The body is short and densely pilose; the epistoma forms an elongated triangle, truncated or very obtuse at the end; the salient palpi are terminated by a long and cylindrical joint; the maxillary lobe is long, narrow, salient at the extremity and destitute of teeth; the abdomen large, and the posterior legs long. PAoHYONEMus, Lepel. and Serv.-Melolontha, Tric!tius, Fab. The elytra narrowed near their extremity, thighs and tibic:e of the two posterior legs inflated, the latter almost cia vate, with one of the two extreme spurs much stouter than the other. ANISONYx, Lat.-Melolontha, Fab. The elytra forming a long square, rounded posteriorly; posterior (1) Encyc. Method., article Scarabei'dea. (2) Ibid., idem. {1) Ibid., idem. |