354 msECTA. 



Chrysotoxum, Mdg. — Muuo, Fab., 

 Where the seta is also inserted on the third joint, but near its base ; 

 this joint is the longest of all, and forms a narrow and elongated 

 triangle ; the two others are almost of equal length. The wings are 

 distant *. 



Sometimes the seta, always thick and in the form of a stilet, ter- 

 minates the antennae. 



Ceria, Fab. 

 Where the body is oval, elongated, and resembles that of a Wasp ; 

 the second joint of the antennae is of equal length with the last, and 

 forms with it a fusiform club with a very short stilet. The abdomen 

 is long and cylindrical. The wings are very remote, and the exte- 

 rior cell of the posterior margin has a well-marked re-entering angle 

 in the outer edge f. 



Calucera, Metg.t 

 Where the body, shorter, wider and silky, has the general appearance 

 of that of the common Fly. The second joint of the antennae, 

 shorter than the last, forms with it an elongated, compressed, fusiform 

 and slightly arcuated club ; the seta is in the form of an elongated 

 stilet ; the first joint is longer than the following one. The exterior 

 cell of the posterior margin exhibits no emargination in its sides +. 



The nasal tubercle which distinguishes the preceding Syrphidae, 

 disappears in the following ones. The seta of the antennae is almost 

 always simple. The wings are incumbent, one on the other. 



The first are connected with the preceding ones by the length of 

 their antennae. Those organs are closely approximated at base ; the 

 second joints, the shortest of all, forms, with the third, a narrow and 

 elongated club ; the seta is simple and inserted near the base of the 

 latter. 



Ceratophya, Wied. 



Scutellum unarmed ; third joint of the antennae nearly twice the 

 length of the first §. 



Aphritis, Lat. — Mulio, Fab. — Microdon, Meig., 

 Wliere the scutellum presents two teeth ; the first joint of the an- 

 tennae is almost as long as the two following ones taken together. 



In this and the preceding subgenus, as in Ascia, the two first 

 closed cells of the posterior edge are terminated in the manner of an 

 angle ||. 



The antennae of the following Syrphidae are shorter than the head. 



The posterior legs are often large, particularly in one of the sexes. 



Sometimes the pallet of the antennae is oblong and almost in the 

 form of an elongated triangle. The posterior thighs are thick and 

 dentated. The wings are incumbent, one on the other. 



* Sec Latreille and Meigen. 



f See Fab., Lat., Meig., and Wiedemann. 



♦ See Lat., Meig. 



§ Wied., Anal., Entom., fig. 9. 



II See Lat., Gen. Crust, et Insect., IV, 329 ; Meig. and Fallen. 



