10. 
Il. 
13. 
14, 
LZ, 
18. 
1: 
20. 
21. 
ENTOMOLOGY 867 
First and second antennal segments both elongate or swollen; the second distinctly more 
than half the length of the first, often equally long or even longer; the third segment 
composed of five main divisions. Frons broad in the female, often wider than long. 
Ocelli present. Eyes bare, in life with zigzag spots or streaks............... Chrysops. 
First and second antennal segments short; the second as a rule not more than half the 
Me snet Mane ele a EM a Ao sh cals Ah aew sa bi voce egal a Pa viel coma Bodice Ake ASL RES Bee 9, 
. Third antennal segment composed of five divisions, the basal division with a long, finger- 
shaped process. Ocelli present. Eyes bare. First and fourth posterior cells open... 10. 
Basal division of the third antennal segment without finger-shaped process, at most 
SCL TILe OM ONONCEN taGMANOU: 4.5 4 she'd sai seas oad eal aDe¥a cee nel kaa da pad oa 
Terminal segment of palpi swollen, crescent-shaped. Subeallus (bearing the antennae) ) 
very prominent. Abdomen flattened, narrowed posteriorly, the apical segments 
ROPE re OOEG. OG MUG OM oir. dcrsns Why hy Kew by Vdlad oa ¥0o 4 vo ae d be wa se Hinea. 
Terminal segment of palpi very elongate, slender. Subcallus (bearing the antennae) 
not particularly prominent. Abdomen of the usual shape............... Tabanocella. 
The four terminal divisions of the slender portion of the third antennal segment more 
or less fused (so that the segment consists of only two distinct divisions). Ocelli 
present. Eyes bare. First and fourth posterior cells, as a rule, open (the first rarely 
GEC HELO RE He MALO y ia cetera. say cca Hs ae Bota. sss aA as Ca eS Rhigioglossa. 
The divisions of the slender, apical portion (or style) of the third antennal segment 
distinet, four to.seven. im NUMIDEr). .45 005+. dhu tobe wess ovpoilvinca< a ntw end oowe 12, 
. Third antennal segment composed of four or five divisions. Proboscis usually shorter 
than the head, rarely of the same length or slightly longer.....................- 13. 
Third antennal segment composed of seven or eight divisions. Proboscis long or short, 
Otten puch longerthannthe heads... svese + os 62 dash aow ae Aww ap va dese eee) 23. 
Antennae placed upon a prominent subcallus; face also swollen beneath the antennae. 
Bist and fourtie posterior cells Open... 4 ices wseis. asin e Saeed am eddhe Pe aninson owe a 14. 
Subcallus bearing the antennae not unusually prominent..................0.00.000ee 16. 
Palpi long and slender. Basal division of third antennal segment strongly flattened, 
very broadly oval, only a little longer than wide, with a bluntly projecting edge 
about the middle of the upper margin and a sharper projection at the apex. Orgizomyia. 
Palpl conmacnvony sw Olen: ShOUiG vc d.2 sci. cy « FS eae de. dime RG baal Mave vee nels 15. 
. Basal division of third antennal segment flattened, with a tooth-like projection on the 
ISO? 3, Leal 100101 Na gh ee ep gan ne nen ene ee me Oe rer eee On Guyona. 
Basal division of third antennal segment elongate oval, without tooth or projecting edge 
OVA) NLeaA) |) 9. e18) 102) Ha 1 a a er Thriambeutes. 
. Ocelli absent. First posterior cell closed before the margin; the third open. Proboscis 
longer than the head. Palpi very short, pointed and slender............. Metaphara. 
WEI ERE e rs ran ers: ul 8! Wat dey, cord d adnate As hoes Ak Hired acd Kuimw ans Cavite wach 17. 
First and fou*th posterior cells both closed and stalked before the margin. Eyesbare... 18. 
First and fourth posterior cells open; rarely closed just at the margin............... 20. 
First posterior cell short-petiolate, the stalk at most slightly longer than that of the 
fourth posterior cell. Proboscis short, with large labella. A narrow frontal callus 
Lio eet RReU RCMUE MULAN Cera in aiwe. Stains, 4 4ir HIG OP Aibieny) aiid ieicutig A 4 ix, acs Ho; as Tj eeea as 19. 
First posterior cell long-petiolate, the stalk two to three times as long as that of the fourth 
posterior cell. Proboscis slender and elongate, with narrow, elongate labella. Frontal 
callus absent in the female. Basal division of third antennal segment with even 
Dep OT RRO, pal pos mia, vo ver mc as Wie Perea Pl Be a dag a kaw a6 6 pd owe Aegophagamyia. 
Basal division of third antennal segment with a projecting blunt edge on the upper 
THESE hl AP Se lee RRR en a ts RU Gk ne ep ee Cae me oe Bouvieromyia. 
Basal division of third antennal segment with even upper margin............... Triclida. 
Frons very wide and parallel-sided in both sexes, much broader than long in the female. 
yes pubescomta EAE SMONGs iy. 9.60% «en Vows hs Sons he ose seule eas dwlaas Pronopes. 
Frons in the female longer than broad or at most as wide as long; linear or absent in the 
PRES VOSA EC Ole MOCO cua res Gr Me Piece ans Ah oe ed vex ea an Ph oe PS 21. 
Third antennal segment composed of four distinct divisions only. Eyes pubescent. 
Brows nt thetemale without basal calls: .. 0.0. cio. eee ee cee dae Dasycompsa. 
Third antennal segment composed of five distinct divisions.......................... 22. 
