336 THE STUDY OF INSECTS 



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

 Abdomen with from three to six exposed segments. Brilliantly metal- 

 lic. ] i. 356 Cleptida; and Chrysidid^e 



FF. Abdomen with eight exposed segments, the petiolar segment short 



and scarcely perceptible. Ovipositor a sting Bethylidce 



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

 teen, 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 re- 

 curved or hooked or otherwise modified. Venation usually well preserved. 

 D. The pronotum extending laterally directly to the tegulae, where its lateral 

 prolongations do not terminate in the form of a rounded "posterior lobe" 

 covering the spiracles. 

 E. Cell M4 of the fore wings longer than cell Cu + Cuj. Lateral prolonga- 

 tions of pronotum forming a posterior angle which lies above the tegulae. 



Wings usually longitudinally plaited, p. 364 VESPlDiE 



EE. Cell M4 of the fore wings shorter than cell Cu + Cui or absent. Lateral 



prolongations of pronotum bluntly rounded, not lying dorsad of the 



tegulae. Wings never longitudinally plaited. 



F. Mesopleura divided by a transverse suture into an upper and lower 



plate. First and second abdominal sternites imbricate. Coxae very 



large and long; the legs long and usually distinctly spinose. p. 355 



Pompilid;e 



FF. Mesopleura not divided by a transverse suture. Coxae and legs not 



unusually long. 



G. First abdominal segment united by a ball and socket joint to the 



second, and itself forming an almost completely separated "scale" 



or "node." Hypopygium of male unciform. Females winged; a 



worker caste present. (Some more primitive genera of ants.) 



p. 357 Formicid^e 



GG. First abdominal sternite attached to the second by a suturiform 

 articulation or more or less imbricate, the first segment not forming 

 a "scale" or "node" between the propodeum and the gaster.* 

 H. Mesosternum not forming with the metasternum a continuous 

 plate overlying the bases of the hind and middle coxae. Axillary 

 excision of the hind wings in normal position, apex of male ab- 

 domen without three retractile spurs between the last tergite and 

 its sternite. 

 I. Vein M4 + Cui of the fore wings opposite vein m-cu or nearly so. 

 Second and third tarsal segments of the female not dilated. 

 J. Mesosternum with two laminae which overlie the bases of the 

 middle coxae. 

 K. Little or no constriction between the first and second 

 abdominal sternites, which are almost or somewhat 

 imbricate. Hypopygium of male not unciform. Both 



sexes winged Anthoboscida 



KK. First and second abdominal sternites separated by a 



strong and distinct suturiform articulation and either the 



hypopygium of the male is unciform, or the females are 



wingless and carried about by the males in mating. 



L. Hypopygium of the male not unciform; but sometimes it 



is tridentate at apex. Females apterous and carried 



about by the males in mating. First submarginal cell 



usually divided by a weak vein (base of the radial 



sector) Thynnidce 



LL. Hypopygium of male unciform, known American fe- 

 males winged. First submarginal cell not divided (base 

 of R s wanting). 

 M. Diurnal insects with normal eyes and ocelli. Fe- 

 males winged. (Tiphiinae). p. 356 Tiphiid/E 



* Some genera of Mutillidae in which the first or first and second abdominal 

 segments are more or less nodose may be recognized as falling in this category by 

 thr unciform hypopygium of the males, the apterous females, and the absence of a 

 neuter caste. 



