634 



L\SECTA. 



the appearance of Common Flies ; the wings not vibratile ; the antennae inserted near the forehead, 

 always shorter than the head, terminated by a long or linear joint, with the seta mostly plumose ; the 

 legs are of moderate size, and the abdomen composed of four joints. 



Anthomyia, Meig., has the seta of the antennae plumose ; the abdomen in both sexes pointed at the tip, and the 

 proboscis not terminated like a hook. Musca pluvialis, Linn. 



Drymeio, Meig., has the proboscis exhibiting this character, and the eyes united behind, in the males. 



denosia, Meig., has the abdomen of the males swollen at the tip. The larvae of C. fungorum live in boleti, and 

 often in the edible mushroom. De Geer observed, also, that these larvae will destroy each other. 



Eriphia, Meig., has the antennae shorter, with a simple style, and the eyes of the males united behind. 



Our third division, Hydromyzides, has the head almost triangular, with the eyes very prominent ; a 

 swollen and vaulted muzzle ; a very thick proboscis ; and the sides of the face not bristly ; the antennae 

 are very short, with the style plumose : the legs are strong. All the indigenous species are found in 

 aquatic situations. 



Ropalomera, Wied., has all the thighs swollen, and the face has a frontal tubercle. 



Ochthera, Latr., has the thighs of the fore-legs very robust, denticulated beneath ; the tibiae curved, and applied 

 against the thighs, and terminated by a strong spine. In the following Hydromyzides, the thighs are not 

 swollen. 



Ephydra, Fall., has the eyes very prominent ; the muzzle thick ; and the seta of the antennae thick at the base, 

 and simple. 



Notiphila, Fall., has the head rounder, without a frontal muzzle. 



The Muscides of the three following divisions have the body oblong ; the wings incumbent, not vi- 

 bratile ; the head nearly spherical, and the face covered by a white membrane, with an impressed line 

 on each side. The antennae are sometimes inserted in fossulae, but oftener porrected, and in many 

 as long or longer than the head. 



The fourth division, Scatomyzides, are distinguished by the head being never longer than broad, 

 nearly spherical ; the hind legs not greatly elongate ; the antennae, with the third joint longer than the 

 preceding, and, except in Loxocera, always shorter than the head. 



Some have the hind legs large, with thick compressed thighs ; and the antennae very short ; with a simple seta. 



Thyreophora, Latr., has the antennae lodged beneath a frontal prominence; and the second and followingjoints 

 of the tarsi nearly alike. T. cynophila, Panz., has the scutellum bispinose ; it is almost always found on the dead 

 carcases of dogs, and M. Percheron has assured me it is sometimes phosphorescent. 



Sphterocera, Latr. (Borborus, Meig.), has the antennae exposed, with the palette hemispherical ; the hind thighs 

 are compressed, with the two basal joints of the tarsi evidently larger than the following. It is almost always 

 about manure that these Diptera are found, and it is probably there that their larvae reside. 



Sometimes the hind legs do not materially differ from the others ; the antennae are nearly as long as the face, 

 deftexed, and terminated by an elongated, narrow palette. 



Dialyta, Meig., has the face bristly ; the abdomen 4-jointed, and the seta of the antennae simple. 



Cordylura, Fall., has the face bristly ; the abdomen 5-jointed, and the wings scarcely extending beyond the 

 abdomen. 



Scatophaga, Latr., differs from the last in having the wings longer than the abdomen, which is never clavate. 

 Musca stercoraria, Linn., a very common buff-coloured species, found in great numbers upon excrement, in which 

 the females deposit their eggs. 



Loxocera, Latr., has the face not bristly ; the body long, narrow, and the antennae much longer than the head. 



Chyliza, Fall., has the antennae shorter than the head, with the seta thick, like a style. 



The others have the antennae always much shorter than the face, with the palette either oblong, ovoid, or 

 nearly globose. 



Some of these have the body narrow and elongate, and the abdomen pointed or stylate ; sometimes the face 

 is naked. 



Lissa, Meig., has the upper side of the head with an elevation, and the abdomen is almost linear. 



Psilomyia, Latr. (to which Geomyza, Fall., may be added), has the body less elongate, and the abdomen ter- 

 minated by an articulated style. 



Tetanura and Tanypeza, Meig., are allied to the preceding; the legs in both seem longer, and the abdomen of 

 Tetanura is obtuse at the tip, and that of Tanypeza pointed or stylate in the females. 



Lonchoptera, Meig., has the face bristly at the sides, and the basal joint of the antennae is verv slender ; the 

 wings have no transverse nerve, except close to the base. 



The body in the other Scatomyzides is thicker and more oblong, and its form is more like that of the common 

 House-fly. 



Heleomyza, Fall., has the head bristly. 



Dryomyza, Fall, (with the face concave beneath the antennae), and 



Sapromyza, Fall, (with it straight), differ from the following in having the antennal seta plumose. 



