036 Div. 3. APtTICULATA— IXSECTA. Class 3. 



Plutiistoma, Moip:., differs in having- tlie head more compressed transversely, so that tlie upper surface is more 

 slanting', and tlie antenna; appear inserted in the middle of the face. 

 Tliis naturally conducts us to Timia, "NVied., and Mosillus, belonging to the next division. 



The eighth division, Gymxomyzides, is composed of small Muscides, with a short body, curved, 

 nearly glWjrous, of a shining black colour, the head much compressed transversely, as in Platystonia, 

 without any inferior prominence ; the scntellum advanced; the abdomen short, depressed, and somo. 

 times terminated by a small point, and the legs nearly glabrous. 



Celyphus, Dalra. (having: the scutellum extended over the body), and 



Lauxauia, Latr. (with the scutellum of ordinary size and the seta plumose), have the antennae longer than the 

 bead. The others have them shorter. 



In some of these they are very short and wide apart, and lodged in impressed fossulcc, the space between them 

 being elevated. 



Mosilliis, Latr., has the first cell of the posterior edge of the wings almost closed j Meigen divides them into two 

 subgenera, — Timia, with the abdomen 6-jointed, and Ulidia, with it 5-jointed. 



Homalura, Meig., with the abdomen .5-jointed, and 



Actora, Meig., with it C-jointed, have the first cells of the posterior limb of the wings entirely open and 

 longitudinal. 



In others the antennie are nearly contiguous, and the cells of the posterior edge of the wing are always open. 



Gi/mnomijza, Fall., has the .nntenns inserted beneath a sort of arch, and near the middle of the face. 



Lonchcea, Meig., has them inserted higher, without any appearance of an arch. 



The second section of the Muscides, and which forms our ninth and last sub-tribe, the IIypocera, 

 consists of a single subgenus, distinct from all the preceding in many respects. The palpi are always 

 external ; the antenna; inserted near the oral cavity, very short, terminated by a large globular joint, 

 with a very long seta ; the wings have only three oblique discoidal nerves, whence the name Trineura 

 given to them by Meigen ; tlie legs are very short and spiny, with the thighs large and compressed, 

 especially in the hind legs. They are extremely active, and form tlie genus Phora, Latr. ; TrU 

 ncura, Meig. 



Our second general section of the Dipterous insects differs from the preceding in the 

 mouth, antenna;, and transformations, and other less important characters ; whence Dr. Leach 

 was induced to form them into a distinct order, Omaloptcra. Tliose which terminate this 

 section have a certain relation with the hexapod wingless inscctSj composing our order of 

 Parasites, or the genus Pedicitlus of Linnaeus. 



This section forms 



THE SIXTH FxVMILY OF THE DIPTER.\,— 



The Pupipara (or the Nymj)hipara of Reaumur). 



The head of these insects, seen from above, is divided into two principal portions, the posterior 

 being the principal, supporting the eyes and receiving the anterior part in an emargiiiation in front. 

 This is also divided into two parts, the posterior being the largest, and supporting the antenna; at its 

 sides; and the other constitutes the mouth organs. The inferior and oral cavity of the head is occu- 

 pied merely by membrane, out of the extremity of which the sucker protrudes, arising from a small 

 bulb, or advanced peduncle, composed of two setaj close together, and covered by two coriaceous, 

 narrow, elongate and villose plates, which act as sheaths. M'hether these valves represent, as I pre- 

 sume, the palpi of other Diptera, or whether they are pieces of a sheath projicrly so called, as regarded 

 by M. Dufour, who has discovered two small bodies, which he takes for palpi; it is not less certain 

 that the proboscis of these insects differs materially from that of the preceding Diptera, and that tlie 

 proboscis has in this case more resemblance to that of the Fleas, from which it is, however, removed 

 l)y the absence of articulations. In Melophagns the base of the jilatps of the sucker is covered by two 

 small, coriaceous, triangular pieces, united, and forming a kind of lalninn ; they seem to represent, in a 

 small degree, the two pieces which cover the base of the rostrum of the Flea. 



The body is short, broad, flat, and defended by a solid or leathery-like skin. The head is more 

 intimately united to the thorax than in the preceding families. The antennae, always situated at the 

 lateral and anterior extremity of the head, appear either under the form of a tubercle bearing three 

 setjE, or that of small hairy plates. The size of the eyes varies, being very small in some species. In 



