== 10. 
11. 
12. 
13. 
14, 
15. 
16. 
17. 
18. 
DIPTERA. 
. Abdomen with discal and marginal macrochetz . 
Abdomen only with marginal macrochetz 
. Autenne inserted on a line drawn through the middle of ‘the 
eyes; vibrissal swellings * parallel 
Antenne inserted above a line drawn through the middle of the 
eyes; vibrissal swellings divergent towards the oral margin. 
Cheeks below the eyes at least as long as half the longitudinal 
diameter of theeyes . . . . . . ee . 
Cheeks below the eyes very narrow, the eyes descending to 
the inferior part of the head or nearly so 
Apical cell closed and sometimes petiolated . 
Apical cellopened . . . . . se 
Posterior cross-vein beyond the middle between the small 
cross-vein and the curvature of the fourth vein. . 
Posterior cross-vein before the middle between the small 
cross-vein and the curvature of the fourth vein 
Face in the middle distinctly carinated. . 
Face not carinated oe 
Antenne nearly as long as the face . 
Antennz much shorter than the face . . . cn 
Antennz inserted on a line drawn through the middle of the eyes. 
Antenne inserted on or below a line drawn through the middle 
oftheeyes . . .... 2... ee . 
Arista short-haired ; posterior cross-vein in the middle be- 
tween the small cross-vein and the curvature of the fourth 
vein . oe . woe ee 
Arista distinctly plumose ; posterior cross-vein beyond the 
middle between the small cross-vein and the curvature of 
the fourth vein... , . . 
Eyes small; their longitudinal diameter less than the length 
of the cheeks beneath them . woe . . 
Eyes of usual size; their longitudinal diameter larger than 
the length of the cheeks beneaththem . . . . . 
Costa of the wings bristly and with a costal spine ; posterior 
cross-vein in the middle between the small cross-vein and 
the curvature of the fourth vein. 
Rhynchodexia, Big. 2 2 5” 
Myocera, Rob.-Desv. 236 
Tromodesia, Rond. 2 3‘) 
Stomatodexia, Br. & v. B. 23 g 
11. 
23. 
12. 
13. 
Megaparia, v.d. Wulp. 2 4 0 
Microchetina, v.d. Wulp. 2 4 0 
14, 
15. 
Camarona, v.d. Wulp. 24) 
Dexia, Meig. 29 
16. 
17. 
Acronacantha, v.d. Wulp. 2-4 3 
Dexiosoma, Rond. 2. 47¥ 
Macrometopa, Br. & v.B. 2YS~ 
18. 
Stenodexia, v.d. Wulp. 244 
* By the term “ vibrissal swellings” I mean the lower part of the elevations which on both sides of the 
face descend from above the root of the antenne, and between which the antenney (in the “ Muscide Caly- 
ptere”) usually rest in a more or less deepened groove, this in the Dexine being often divided into two parts 
by a longitudinal carina in the middle. 
The vibrissal swellings are seldom wholly parallel, but in most of the 
genera convergent towards the oral margin, forming a blunt angle, on which the vibrisse are inserted. Brauer 
and von Bergenstamm in their very interesting work on the “ Muscaria Schizometopa” [Denkschr. der kais. 
Akad. der Wissensch. Wien, lvi. (1889)] have attached considerable importance to the shape of these eleva- 
tions (Vibrissenleiste, Vibrissenwulste, Vibrissenecke), which sometimes offer good generic characters, though 
they have been totally neglected hitherto. 
