ZOOLOST. 221 



5. Tabanus. Moulh with a fleshy strait proboscis, termi- 



nating in two equal lips : antenncB short, placed near 

 together ; in some species furnished with a projecting 

 tooth near their bases ; rostrum with two pointed 

 feelers, situated on each side, and parallel to the pro- 

 boscis. 



Many of this tribe greatly resemble the last genus, they 

 are exceedingly troublesome to various kinds of Quadrupeds, 

 feeding on the blood %vhich they suck out through their pro- 

 boscis ; their larvae are found in moist grass places. 



6. Culex. Gnat. Antenna: filiform, in some species simple, 



in others, beautifully feathered ; either in whorls, as at 

 fig. 38, or simply feathered, as fig. 39, plate 3 ; mouth 

 consisting of setaceous pzercer J contained within a flex- 

 ible sheath. 



These well known insects derive their subsistence in the 

 manner of the preceding genus, by sucking the blood of large 

 animals; in the larvas state they are aquatic, and feed on the 

 smaller kinds of water insects, which abound in stagnant 

 waters ; they are of very singular forms, and are objects 

 particularly suited for the Microscopic observer. 



7. Empis. Antennce setaceous, in others formed of three 



joints, the first of which is lanceolate, fig. 40, plate 3; 

 mouth formed of a horny inflected bivalve snout longer 

 than the thorax. 



These insects live like the preceding genera, by sucking 

 out the blood of other animals. 



