452 INSECTA. 



The remaining Tanystoma of our first division usually have a short, wide 

 body, the head applied directly to the thorax, the wings distant, and the 

 abdomen triangular. In a word, their general appearance is that of our 

 domestic fly. Their proboscis is frequently long. 



CYRTUS, Latreille, 



Intermediate between Empis and Bombylius. The wings are inclined on 

 each side of the body ; and the alulte very large and covering the halteres ; 

 the head is small and globular, the thorax very high or gibbous, the abdomen 

 vesicular and rounded, or almost cubical ; the antennae are closely approxi- 

 mated, and the proboscis is directed backwards or wanting. 



BOMBYLIUS, Linneeus BOMBYLIERS, Lalreille, 



Where the wings are extended horizontally on each side of the body, and 

 the halteres are exposed. The thorax is higher than the head, or gibbous as 

 in Cyrtus; the antennae are closely approximated, and the abdomen is trian- 

 gular or conical ; the proboscis is directed forwards. The proboscis is generally 

 very long and most slender at the extremity. Their legs are long and attenu- 

 ated. They fly with great velocity, hover over flowers without alighting on 

 them, introduce their trunk into the calyx to obtain their nectar, and produce 

 a sharp humming sound. 



ANTHRAX, Scopoli, Fabricius. 



Similar to Bombylius; but where the body is depressed, or but slightly 

 elevated and not gibbous, with the head as high and as broad as itself. The 

 antennae are always short, and distinct from each other, and always terminated 

 by a subulate or punch-like joint. The proboscis, except in a small number, 

 is generally short, extending but little beyond the head, frequently even 

 withdrawn into its oral cavity, and terminated by a little inflation formed by 

 the lips. The palpi are usually concealed, small, filiform, and each, at least in 

 several, adhering to one of the threads of the sucker. The abdomen is less 

 triangular than that of the Bombylii, and partly square. These insects are 

 generally hairy. Their habits are very analogous to those last mentioned. They 

 frequently alight on the ground, on walls exposed to the sun, and on leaves. 



Our second general division of the Tanystoma is characterised by a mem- 

 branous proboscis, usually with a short stem, projecting but slightly, and 

 terminated by two very distinct and raised or ascending lips. 



The form of the head in the larvae of the last Diptera of this division is 

 variable. 



In someLeptides the wings are distant and exhibit several complete 

 cells. The antenna? are not terminated en palette. The palpi are filiform 

 or conical. 



Sometimes these palpi are withdrawn into the oral cavity. The antennT 

 have a fusiform termination or one resembling an elongated cone, with a little 

 articulated stilet at the end. 



