HYMENOPTERA 913 



MM. Nocturnal insects with enlarged eyes and ocelli. 

 The marginal cell (2d Ri + R2) removed from the 

 apex of the wing by several times its length. Fe- 

 males unknown but presumably apterous. (Brachy- 



cistinae.) p. 953 Mutillid^ 



JJ. Mesosternum simple or with two minute erect teeth 

 between the bases of the coxas. 



K. Marginal cell (2d Ri + R2) removed by less than its 

 length from the wing apex; the fourth submarginal cell 

 (R3) not traversed by an adventitious vein. Abdomen 

 never petiolate. > 



L. No constrictions between the abdominal segments 

 (except between the first and the second), all tergites 

 and all but the first and second sternites loosely im- 

 bricated plates. The last tergite of the male a small 

 simple lamina. Edges of the hypopygium of the fe- 

 male turned upwards and meeting on the mid-dorsal 

 line, often fused, enclosing the sting in a cone. Both 

 sexes winged. Vein m and M2 of the hind wings 

 wanting. Mesosternum unarmed, upper surface of 



hind coxae simple, p. 952 Sapvgid^ 



LL. Strong constrictions between each of the ab- 

 dominal segments, the tergites and sternites all 

 heavily chitinized and not loosely imbricate; the 

 last tergite modified and hood-like. Female apterous. 

 Upper surface of the hind coxae, at least in the male, 

 with a lamella. (Methocinseand Myrmosinae.) p. 953- 



TlPHIID^ 



KK. Marginal cell (2d Ri + Ro) removed by two or more 

 times its length from the apex of the wing; cell R.3 when 

 present usually traversed by a longitudinal adventitious 

 vein. Often nocturnal insects with large eyes and ocelli. 

 Females apterous. (Several subfamilies.) p. 953. 



MUTILLID.^ 



II. Vein M4 + Cui of the forewings more than two-thirds its 

 length apicad of vein m-cu. Second and third tarsal seg- 

 ments of the female dilated, deeply excised, and filled with 

 membrane between the lobes. Nocturnal insects with very 

 large eves and ocelli. Petiole long and slender. Hypopygium 



unarmed, p. 965 Rhopalosomid^ 



HH. Mesosternum and metasternum together forming a con- 

 tinuous plate overlying the bases of the hind and middle 

 coxae, separated from each other by a transverse suture. 

 Axillary excision of the hind wings almost opposite the apex of 

 cell Ms -f Cui + Cu. Abdomen of male with three spines, 

 retractile between the last sternite and tergite. Tongue elon- 

 gate. Wings with membrane striolate. p. 954 Scoliid/E 



DD. Pronotum terminating behind laterally in the form of two clearly 

 differentiated rounded "posterior lobes," covering the spiracles. These 

 lobes reach the tegulas in North American forms only in the extremely 

 rare genus Dolichurus. 



E. Posterior metatarsus not dilated. No plumose hairs. Females 

 without pollen- collecting apparatus, but often with a comb on the an- 

 terior tarsi. Maxillae rarely elongate; if so, either the ocelli are 

 distorted, or the abdomen has a petiole composed only of the first 

 sternite. 



F. Abdomen of the male with only three or four exposed tergites. 

 Last sternite of the female enclosing the sting, its edges fused in the 



mid-dorsal line. (Dolichurinae.) p. 978 Ampulicid^ 



FF. Abdomen of the male with seven exposed tergites. Stmg not en- 

 closed by the hypopygium. p. 979 Sphecid/E 



