G28 INSECTA. 



tlie third joint shorter, nearly nvoid, and the fourth joint shorter, the style not terminal, but dorsal. 0. ITif 

 poleon, Fab. 



Nemotvln.'i, Geoff., differs from the precediiif^ in havin;;: the proboscis lonj^;, siphon-shaped, ell^owtd at the 

 base, and lodged in a fi-ontal protuberance of the head, likf a beak. 



In the others the third joint of the antennre forms, with the preceding, an ovoid or (^lobular mass, terminated 

 by a loiip seta. The sculellura is rarely spined. 



Chnj^Qchlora, Latr. (Sargus, Fab.), has the third joint of the antenna; conic, and terminated iiy a seta. 



Sargu-Sy Fab., has the same joint subovoid, or nearly globose, rounded, or obtuse at the tip, with the seta^dorsal- 

 The first joint is nearly cylindrical ; the scutellum rarely spined ; the body often elonj^ate, green, or coppery, and 

 brilliant. Musca cupraria, Linn., a very common species, the larva of ivhich resides in cow dung, and is of an 

 oval, oblong form, narrowed and pointed in front, with a scaly head furnished with two hooks. It becomes a pupa 

 beneath its own skin, and without materially altering its form. 



Vappo, Latr. (Pac/n/gaatfr, Meig.), differs chiefly from Sargus in the antcnuK being sJiorter, ^vith the Ijasal joints 

 transverse. 



Our seconil general division of those Diptera which have a sucker received in the ]irohoscis, 

 or sheath, and the antennae only 2- or 3-joiuted, comprises those which have the ])rohoscis 

 generally memhranous, bilahiate, long, elbowed, and hearing two palpi implanted a little 

 above the elbow, and most commonly received into the oral cavity, and has only two pieces 

 in the sucker, when it is always protruded. The last j(.unt of the antenna;-, aUva3's furnished 

 \\ith a style or seta, has no annular division. The palpi arc hidden in repose. This chvision 

 forms 



THE FIFTH FAMILY OF THE DIPTERA,— 

 The Athericera, — 



The proboscis of "which is generally terminated by tv^-o large hps ; the sucker "has never more than 

 four, and often only two pieces. The larv^ have the body very soft, contractile, annulated, narrower 

 ill front, with the head of a variable figure, and its external organs consisting of one or two hooks, 

 accompanied in some genera with fleshy lobes, and probably in all with a sort of tongae destined to 

 receive the nutritive fluids. The spiracles are four in number; two placed in the prothorax, and two 

 at the extremity of the body, on scaly plates ; each of the latter is formed, ia many, of three small 

 spiracles close together. These larvcc do not change ihcir skins ; that which tlicy fir^t possess hn-dens, 

 and bec-omes a kind of cocoon for the }inpa. It also shortens, and assumes an oval form ; the anterior 

 l»art, wliich was slenderest in the larva, thickens. AVe also discover in it traces of articulation, and 

 often vestiges of spiracles, although they no longer serve for resjiiration. [The maimer in which the 

 transformation to the pupa state is etfectcd, is described in the general observations on ihc order, and 

 need not be repeated.] 



Few of the Athericera are carnivorous in the perfect state. Tlicy are found, for the most part, on 

 flowers, leaves, and sometimes on human excrement. 



This family comprises the genera Conops, (Es/rus, and the major part of that of Musca, of 

 LinuKus, 



We naturally commence with those species of the latter genus, which have the sucker formed of 

 four pieces and not of two, as in all the other Athericera. Thry lorm a tir^t trilie, SvupriiD.-E. 



The proboscis is always long, membranous, elbowed near the haiNC, tci-minatcd by two largo lips, and 



the sucker inclosed in an u[>[.icr canal ; tlie upper piece of the sucker is thick, and notclied at the tip, 



the others are sleiuicr ; to each of the two labial ones, representing maxilkT, is attached a smaD, 



slender palpus ; the head is hemispherical, and occupied for the most part by the eves, cspeciallv in 



the males, its anterior extremity is mostly [iroduced like a iuu7,zle, or beak, receiving the proljoscis 



\\heu it is folilcd in inactiun. Many species resemble Humblc-ljces, and others Wasps. Thii tribe 



comprises Ijut a single genus, 



SYRrucs, — 



A first general division of which is composed of those wilh the proboscis shorter than the head and thorax. 



Some of these have the front of the bead produced into an eminence above the oral cavity; at tlie head of 

 these are placed such as have the seta of theantenn.T jiluniose ; the body short and liairy, resembling Humble-bees. 



Volucella, Geufir., has the third joint of the antenuie oblong, jts outline furnung a cur\ iliuear and cluii"-ate 

 triangle. 



Musca nnj,-itacea, Linn., a vi.'ry common species, the larva of which lives in the nests of Bombi, its body being 



