74Q M. W. R. de V. GRAHAM 



following tergites with similar sculpture and pilosity. Propodeum nearly 

 or quite as long as the scutellum 



Head, Text-fig. 606 (North America). . . subapterus (Riley) (p. 776) 



Gaster with basal tergite smooth, or rarely with some very weak alutaceous 

 sculpture along its hind margin, bare except at the sides ; the three 

 following tergites also bare except laterally, sometimes smooth though 

 often with some alutaceous sculpture. Propodeum usually relatively 

 shorter than in the above ......... 4 



4 (3) Antenna (Text-fig. 598) with flagellum very stout, nearly twice as stout as the 



pedicellus, subfusiform ; clava broadest across its first segment, thence 

 tapering to apex ; second anellus large, only slightly transverse. Gaster 

 with basal tergite occupying two thirds to three quarters of the whole. 

 Head (Text-fig. 608) fully 13 times as broad as the mesoscutum. (North 

 America) ........ tachinae Gahan (p. 777) 



Antennae (Text-figs. 599-602, 629-640) with flagellum not so stout, usually 

 thickening at least slightly from base to tip ; clava tapering less strongly ; 

 second anellus, except in leguminis, smaller and transverse. Gaster with 

 basal tergite occupying at most about half the total length, but usually 

 less. Head rarely so broad relative to the mesoscutum .... 5 



5 (4) Antenna (Text-fig. 599) with second anellus subquadrate, very hairy, and 



half as long as the first funicular segment ; lower edge of toruli hardly 

 above level of ventral edge of eyes ; scape distinctly shorter than eye. 

 Fore wing with marginal vein at most 1-2 times as long as the stigmal vein. 

 Median area of propodeum (Text-fig. 604) rather strongly transverse. 

 (North America). 



Head, Text-fig. 610 ...... leguminis Gahan (p. 776) 



Antennae (Text-fig. 600-602, 629-640) with second anellus transverse, never 



so hairy as in the above ......... 6 



6 (5) Fore wing with marginal vein at most i-6 times as long as the stigmal vein 7 



- Fore wing with marginal vein more than i-6 (up to 2-2) times as long as the 



stigmal vein ........... 29 



7 (6) North American species with gaster nearly or quite twice as long as broad, and 



about as long as head plus thorax ; antenna (Text-fig. 602) with lower edge 

 of toruli only very slightly above the level of the ventral edge of the eyes, 

 scape nearly as long as an eye, proximal segments of the funicle slightly 

 longer than broad or quadrate. Head in dorsal view (Text-fig. 609) 



americanus Gahan (p. 775) 

 Either European species ; or gaster at most 1-75 times as long as broad, and 



the other characters not all present in combination. .... 8 



8 (7) Antennae with lower edge of toruli at or hardly above the level of the ventral 



edge of the eyes, distance between toruli and front margin of clypeus not 

 or hardly greater than the malar space ; scape, except in maurus sp. n., as 

 long as an eye and reaching the vertex ....... 9 



Antennae with lower edge of toruli distinctly above the level of the ventral 

 edge of the eyes, distance between toruli and front margin of clypeus 

 usually distinctly greater than the malar space ; if only slightly greater, 

 then scape shorter than an eye and not reaching the vertex . . . 14 



9 (8) North American species . . ....... 10 



- European species ........... n 



10 (9) Pronotal collar sharply and evenly margined except just at the sides. Malar 



space slightly more than half the length of an eye. Antenna (Text-fig. 600) ; 



head (Text-fig. 611) . . . . . . viridescens (Walsh) (p. 777) 



