386 INSECTS. DIPTERA. 



b. Rostrum long, slender, filiform, retracted into the lower cavity of an anterior pro- 

 jection in the form of a beak and bearing the antennae. 

 Gen. NEMOTELUS. 



B. Last joint of the antennae forming a globular or oval club, with a long seta at 

 the end ; scutellum generally unarmed. 



Gen. CHRYSOCHLORUS, SARGUS, VAPPO. 

 II. Last joint of the antennas inarticulate, without style or seta. 

 Gen. SCENOPIXUS. 



Gen. STRATIOMYS, Geoff. Lat. Musca, Lin. 



Sucker of at most two setae, received into a very short, retractile, 

 bilobate, and membranous sheath ; antennae of three principal 

 pieces, longer than the head, the second and third pieces 

 forming a compressed fusiform body of about six joints, ter- 

 minated in a point, without style or seta ; head hemispheri- 

 cal ; thorax cylindrical ; scutellum armed with two points ; 

 wings long, resting upon one another ; abdomen widened in 

 the middle ; tarsi with three balls. 



S. chamaleon, Geoff. Head yellow ; eyes brown ; antennae black ; 

 thorax brown, covered with fawn-coloured down ; scutellum yel- 

 low, with two points of the same colour ; abdomen blackish brown 

 above, with seven spots of deep yellow., three on each side and 

 one at the extremity, and bordered by a black ring ; feet yellow 

 and the thighs brown. Europe, on flowers Shaw, vi. pi. 105. 



FAMILY IV. ATHERICERA. 



Sucker of two or four pieces, the two contiguous ones with palpi, 

 retracted with the sucker into a furrow of the trunk. 



TRIBE I. SYRPHLE. 



I. Antennae longer than the head. 



1 . No nasal prominence. 



Gen. APHRITIS, (Microdon, Meigen,) CERATOPHYA, (Wiedem.) 



2. A nasal prominence. 



Gen CERIA, CALLTCERA, SPHECOMYIA, CHRYSOTOXUM. 



II. Antennae almost as long as the head, supported on a common pedicle or sepa- 

 rate, but with their two first joints equal ; a nasal prominence. 



Gen. PARAGUS, PSARUS. 



III. Antennae much shorter than the head. 

 1. Antennae of three joints. 



A. Snout rostriform, projecting ; proboscis very long. 



Gen. RHINGIA. 



B. Snout not projecting or very short ; proboscis of medium length. 



a. Antennae with a plumose or hairy and three jointed seta. 



Gen. VOLUCELLA, SERICOMYIA, ERISTALIS, BRACHYOPUS, PELOCERA. 



b. Seta of the antennae simple and not jointed. 

 * A nasal prominence. 



Gen. MALLOTUS, HELOPHILUS, SYRPHUS, DOROS, BACCA, CHRYSOGAS- 



TER, PSILOTE. 



