HYMENOPTERA 911 



trace of the transverse part of vein M is the only additional 



vein present, there being never any closed cells, p. 941 



Ch.a.lcidid^ 



GG. Wings longitudinally plaited in repose, ovipositor carried 

 along the mid-dorsal line. Pronotum reaching the tegulae, the 



prepectus not being distinctly set off. {Leucospis.) p. 941 



Ch.vlcidid^ 



CC. An erect scale or one or two nodes between the propodeum and the 



gaster. p. 954 Formicid^ 



BB. Hind wings with an anal lobe.* If there are any closed cells in the hind 

 wings the antennae are thirteen-segmented in the male, twelve- in the fe- 

 male, except in a few instances where the number is reduced by fusion, but 

 then the apical segments always form a club, or are abruptly recurved or 

 otherwise strikingly modified (except that in some species of Crabro both 

 sexes have twelve-segmented, otherwise normal antennee). 

 C. Hind wings without closed cells. Number of antennal segments variable, 

 but never thirteen in the male and twelve in the female, nor are the apical 

 segments in the male either formed into a distinct club, or strongly re- 

 flexed or otherwise peculiarly modified. Vein dissolution extensive. 

 D. Abdomen attached to the dorsal surface of the propodeum. p. 949. . . 



EV.\NIID^ 



DD. Abdomen attached normally, at the apex of the propodeum 

 between or slightly above the hind coxae. 



E. AntenncB composed of ten segments, or if of thirteen in the female 

 {Ampulicomorpha) then the pronotum is elongate and has a median 

 longitudinal sulcus. 

 F. Antennae inserted on a frontal prominence distant from the clyp- 



eus; mouth ventral. Fore tarsi simple, p. 951 Embolemid^e 



FF. Antennae inserted close to the clypeus. Fore tarsi of the female 



usually chelate, p. 978 Drvinid^e 



EE. Antenna usually composed of thirteen segments, more rarely of 

 twelve or eleven segments, or multiarticulate. 



F. Abdomen with six exposed segments or less. Forewings always 

 with cells M and Cu + Cui closed. Ovipositor an extensile jointed 

 tube. 

 G. Venter convex; abdomen with six exposed segments, p. 951 . . 



Cleptid^ 



GG. Venter strongly concave; abdomen with at most five usually 

 three or four exposed segments. Brilliantly metallic, p. 951 ... . 



Chrysidid^ 



FF. Abdomen with eight exposed segments, the petiolar segment 

 very short and scarcely perceptible. Ovipositor a true sting, p. 965. 



Bethylid^ 



CC. Hind wings with at least a closed median cell (cell M). Males with 

 thirteen, females with twelve antennal segments, except in rare instances, 

 where they have been reduced slightly below that number in the males, in 

 which case they usually either end in a jointed club or the last segments are 

 recurved or hooked or otherwise modified. Venation usually well pre- 

 served. 



*If there is a very deep or slit-like incision on the margin of the hind wing, the 

 insect is certain to come under this heading. There are some genera of Sphecidae 

 (of the tribes Larrini, Astatini and the subfamily Sphecinae) in which the axillary 

 excision or both axillary and preaxillary excisions are reduced to small and incon- 

 spicuous notches, close to one another, and in some cases the axillary excision is 

 altogether lacking. But in all such cases the second anal furrow is distinct, its 

 apex close to that of the first anal furrow, and it delimits a large anal area behind 

 it, which therefore lacks only the notch itself in order to become a distinct anai 

 lobe. In all insects falling under grouping B this furrow is wanting, due to there- 

 duction or entire absence of the area which in a more primitive condition exists 

 behind it and forms the anal or posterior lobe of the wing. 



