628 Div. 3. ARTICULATA.— IXSECTA. Class 3. 



the third joint shorter, nearly ovoid, and the fourth joint shorter, the style not terminal, but dorsal. O. Hy 

 poleon, Fab. 



Nemoteliis, Geoff., differs from the preccdina; in having the proboscis lonj, siphon-shaped, elbowed at the 

 base, and lodged in a frontal protuberance of the head, like a beak. 



In the others the third joint of the antenna forms, with the preceding, an ovoid or globular mass, terminated 

 by a long seta. The scutellum is rarely spined. 



ChrysocMora, Latr. (Sargus, Fab.), has the third joint of the antenna; conic, and terminated by a seta. 



Sargus, 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 elongate, green, or coppery, and 

 brilliant. Musca cvpraria, Linn., a very common species, the larva of which resides in cow dung, and ;s 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/gasfcr, Meig.), differs chiefly from Sargus in the antenna; being shorter, with the basal joints 

 transverse. 



Our second general division of those Diptera wliicli have a sucker received in the proboscis, 

 or sheath, and the antennas only 2- or 3-jointed, comprises those which have the proboscis 

 generally membranous, bilabiate, long, elbowed, and bearing two palpi implanted a httlc 

 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 joint of the antenna}, alwaj's furnished 

 with a style or seta, has no annular division. The palpi are hidden in repose. This division 

 forms 



THE FIFTH FAMILY OF THE DIPTERA,— , 



The Athericera, — 



The proboscis of which is generally terminated by two large lips ; the sucker has never more than 

 four, and often only two pieces. The larva; have the body very soft, contractile, anuulatcd, narrower 

 in front, with tlie 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 tongue destined to 

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

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

 spiracles close togetlier. Tliese laivx do not cliange their skins ; that which tliey first possess h:irdens, 

 and becomes a kind of cocoon for the pupa. It also shortens, and assumes an oval form ; the anterior 

 part, whicli was slenderest in the larva, tliickcns. 'We also discover in it traces of articulation, and 

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

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

 need not be repeated.] 



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

 flowers, leaves, and sometimes on human excrement. 



This family comprises the genera Cmiojis, (Eslriis, and the major part of that of Musca, of 

 Linna;us. 



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. They form a first tribe, SvurniD.^:. 



The proboscis is always long, mcndjranons, elboweil near the hasc, terminated by two large lips, and 

 the sucker inclosed in an upper canal ; the upper piece of the sucker is thick, and ni)tcbcd at the tip, 

 the others are slender ; to each of the two labial ones, representing maxilla;, is attaelie<l a small, 

 slender palpus ; the head is liemispherical, and occupied for the most part by the eyes, esi)ccially in 

 the males. Its anterior extremity is mostly produced like a muzzle, or beak, receiving the proboscis 

 v\hen it is folded in inaction. Many species resemble Humble-bees, and others Wasps. This tribe 

 comprises but a single genus, 



SVRPUUS,— 



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



Some of these have the front of the hi^ad produced into an rniinence above the oral cavity ; at the head of 

 these are placed sncli as have lh(!stta of tlieaMt( nnri- plumose ; thi' body short and liHiry, resembling Iluinblo-bees. 



Volncdla, (juollV,, has the third joint of the anlcnnie oblong, its outline Ibrniing u curvilinear and elongate 

 triangle. 



Musca mystaceu, Linn., u very connnun specie?, the lai va of «lilch lives in the nests of lloinbi, its li'MJy boing 



