| OCR Text |
Show 292 INSECTA. of the two genera above mentioned, is amply sufficient for the actual wants of the science. Dr Desvoidy has employed but very few characters of his own in designating these groups. There are even ~orne~ ';hich he might have used to advantage, such as the dtspostbon of the nervures of the wings, which he has neglected, at least in the work presented to th~ Academy. His first family, th t f the Calunterees is identical with the one I call Creo-phail eos in my ". tFra mille' s N aturelles du Re' gne A m.m a 1" and which besides, was already established in my preceding works: According to the analysis of his Memoir given by M. de Blainville, it is evident that the characters of the nine other families of the Myodaires are generally founded on the mere diversity of their mode of habitation, their colours, and on some other vague considerations. We will endeavour to arrange the genera of Messrs Wiedemann and Fallen which we have been able to study, in our former method, but with some modifications which the observations of these celebrated naturalists, and others of my own, render necessary. This tribe will comprise the genus MuscA, Lin. Antennre inserted near the front, palpi placed on the proboscis, and retiring with it into the oral cavity, and transverse nervures in the wings, characterize a first section of the winged Muscides, which will include eight principal groups or sub-tribes. Those of our first division, the CnEOPl-IILJE, have large alulre which almost completely cover the halteres. The wings are almost always distant, with the two terminal and exterior cells of the posterior edge(l) closed by a transverse nervure. ( 1) The most external one is situated under a narrow, elongated cell, closed by the posterior margin, which may be considered as a sort of ~ubital cell. In the following divisions, this exterior cell is not clos~d by a transverse nervure. T~e second, or that which adjoins the inner side of the preceding one, is also closed 11~ the last of the Muscides; but it is no longer terminal, and frequently it is even DIPTERA: 293 Of the species which always present these characters ·we will distinguish those whose epistoma does not project in the ~anner of a rostrum, and the side& of whose head are not prolonged in the form of horns. In some, the seta of the antennre is simple or without any very apparent hairs. In one single subgenus EoHINOMYlA, Dum.-Tachina, Fab. Meig. The second joint of the antennre is the longest of all. The last or the palette is widest, compressed, almost in the form of a reversed triangle or trapezoidal. The seta is biarticulated inferiorly. E. groaaa; Musca grosaa, L.; De Geer, InseCt., VI, 1, 12. The largest species known, and almost of the size of a Bombus; black, br.istled with thick hairs; head yellow; eyes brown; origin of the wmg~ russet. It hums loudly while on the wing, alights on flowers, m the woods, and frequently on cow-dung. The larva lives in the latter substance; its body is yellowish, glossy and conical, furnished with a single hook and two small fleshy horns at its anterior extremity or the point; the opposite end is terminated by a circular plane on which are two stigmata each formed of a lenticular and brown pla~e raised in the middle: The second annulus of the body, the head counted as one also . ' presents a stigma on each side. The posterior extremity of the cocoon of the pupa, which is also conical, presents two more distinct stigmata; its contour is formed by a nine-sided lamina. See Reaum., Insect., IV, xii, 11, 12; and XXVI, 6-10(1). In the other Creophilre, the third joint of the antennre is longer than the preceding one, or at least is never shorter. Someti~es the anteri?r face of the head is almost smooth, or presents but very short haus, arranged as usual in two longitudinal rows, none of which are roue~ larger than the others. sh~rter; th~ longitudinal nervures which form the sides, are prolonged to the posterior margm, thereby forming another cell, which becomes terminal and incomplete. In the Creophi1a:, the two nervures are not (or but very slightly) prolonged beyond the closed cell. (1~ ~ivisio~ A of the genus Tachina, Mcig. The species called feroz has its palp.1 d1lated m the form of a spatula, and constitutes the genus Fahricia of M, Robmeau. The Stomoxy11 bombilans, Fab., has the facies of the Echinomyia: and the proboscis of the Bucentes. , |
