1969] 
Tho?npson — Microdontine Flies 
81 
2. Pteropleura bare Paragodon Thompson 
Pteropleura pilose 3 
3. Antennae short, less than one-half as long as face; first antennal 
segment never more than twice as long as broad (Fig. 2) .... 
Paramicrodon de Meijere 
Antennae long, always longer than one-half as long as face; first 
antennal segment always much more than twice as long as 
broad (Figs. 4 & 5) Microdon Meigen 4 5 
4. Apical cross-vein angled outward on anterior one-half (Fig. 11) 
Aristosyrphus Curran 
Apical cross-vein not so, straight or slightly curved inward 5 
5. Barrette (dorsal portion of hypopleura) bare 6 
Barrette pilose Rhopalosyrphus Giglio-Tos 
6. Hind tibiae with distinct brushes of pile 6 7 
Hind tibiae without brushes 8 
7. Occiput uniformly developed, collar-like (Fig. 4) 
Rhoga Walker 
Occiput not uniformly developed (Fig. 3) Ubristes Walker 
8. Anterior mesopleura bare; abdomen petiolate, petiole as long as 
thorax or longer; face slightly bulging below 
Cerioimicrodon Hull 
Anterior mesopleura pilose; abdomen usually not petiolate; if 
petiolate, then petiolate short and face not bulging below 
Microdon Meigen 
Key to the species of Paragodon 
1. Face with medial brown stripe; hind tibiae black 
paragoides, new species (Mexico) 
Face without medial brown stripe; hind tibiae whitish yellow .... 
minutula van Doesburg 1966 (Surinam) 
Paragodon paragoides, new species 
Face slightly produced medially, yellowish, with a diffuse medial 
brown stripe; thorax and abdomen brownish with yellow spots; legs 
black except front four tibiae and all tarsi orange. 
Male. Head: face yellowish white except for diffuse medial 
brownish area, with white pile; front and vertex brownish black 
with pale pile; occiput black, grayish pollinose, with pale pile. Face 
narrower at oral opening than width of vertex, widest at base of 
5 On the whole the separation of Microdon into subgenera, couplets 4-8, 
is not satisfactory. I do not recognize these subgenera as anything more 
than distinctive species groups. 
6 Not all Ubristes types have distinct brushes of pile. 
