226 DIPTERA. 
Many of them offer great difficulties, if we endeavour to find suitable characters to 
distinguish them from each other. The following synoptical table must therefore be 
considered merely as an essay, as some of the enumerated species may perhaps prove 
to be no more than varieties :— oe 
1. Abdomen rufous, with a black dorsal band, or at least laterally 
with a well-pronounced rufous coloration . . . . 2. 
Abdomen without distinct rufous coloration at the sides 9. 
2. Legs rufous or with distinct rufous portions . 3. 
Legs black, the tibie at most slightly rufous . oe ew A, 
3. Antenne wholly rufous. . . rutilans, v. d. Wulp. . 
Antenne with the third joint at the tip, or even n for the greater 
part, brown or black . . . . . . . + «discolor, v. d. Wulp. 
4, Wings yellowish, with a rufous venation . . . . . . . tincticornis, Big. 
Wings grey, with the veins brown or black . . . . . . 5. 
5. Cheeks hairy. . . 2. 2. 1 ee ee ee ee ee 6 
Cheeks bare. . . . . oe ro 
6. Hind tibiz slightly curved ; smnaller species ‘(0 millim. or 
less) . . . . . » oe ee 6conjuncta,v.d. Wulp. — , 
Hind tibiz straight ; larger species s (12° 5 milli. . . . « simulans, v. d. Wulp. 
7. Scutellum grey . . 2. 1. 2... we ee ee ee frat erna, v. d. Wulp. 
Scutellum rufous. . . . 2... . ww ee eee 8 
8. Pulvilli yellow . 
scutellata, v. d. Wulp. 
Pulvilli dark grey . 
rubricornis, v. d. Wulp. 
9. Anus rufous rufianalis, v. d. Wulp. 
Anus notrufous . . ... 0... we eee CS 
10. Legsrufous. . . . ...... eee OL 
Legs black . 2. 2. 2... ww we eee ee ee 
11. Coxe black . 
. oe ew ew ee) 6Varipes, v. d. Wulp. 
Coxe rufous .. . . rs 02 
12. Ground-colour of the thorax and abdomen grey . 
Ground-colour of the thorax and abdomen cinereous 
13. Base of the wings and small cross-vein infuscated 
strigilata, v. d. Wulp. 
macroptera, v. d. Wulp. 
punctipennis, v. d. Wulp. 
Base of the wings and small cross-vein not infuscated . . . 14. 
14. Curvature of the fourth vein angular woe es .) angulata, v. d. Wulp. 
Curvature of the fourth vein rounded . . ..... 15. 
15. The black thoracic stripes very distinct; base of the wings 
yellow . . oe oo ~ . . « . striata, v. d. Wulp. 
The black thoracic stripes less distinct ; base of the wings not 
yellow. . 2. 2. 2... ee ee we ee Od 
16. Abdomen unicolorous black or piceous . anthracina, Big. 
Abdomen with cinereous and blackish reflecting spots - . . L%. 
17. Front prominent, flattened . 
. planifrons, v. d. Wulp. 
Front less prominent and slightly convex 
eo ee ew ee 18, 
