HYMENOPTERA 337 



MM. Nocturnal insects with enlarged eyes and ocelli. 

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

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

 males unknown but presumably apterous. (Brachy- 



cistinae). p. 356 Mutillid.* 



JJ. Mesosternum simple or with two minute erect teeth be- 

 tween the bases of the coxas. 

 K. Marginal cell (2d R x + R 2 ) 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 imbricated 

 plates. Both sexes winged. Mesosternum unarmed, 



upper surface of hind coxae simple Sapygidce 



LL. Strong constrictions between each of the abdominal 

 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. 



(Methocinae and Myrmosinas). p. 356 Tiphiid;e 



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

 times its length from the apex of the wing; cell R3 when 

 present usually traversed by a longitudinal adventitious 

 vein. Often nocturnal insects with large eyes and ocelli. 

 Females apterous. (Several subfamilies.) p. 356. 



MUTILLID/E 



II. Vein M 4 + Cui of the fore wings more than two-thirds its length 

 apicad of vein m-cu. Second and third tarsal segments of the 

 female dilated, deeply excised, and filled with membrane between 

 the lobes. Nocturnal insects with very large eyes and ocelli. Pet- 

 iole long and slender. Hypopygium unarmed Rhopalosomidce 



HH. Mesosternum and metasternum together forming a continuous 

 plate overlying the bases of the hind and middle coxa?, separated 

 from each other by a transverse suture. Axillary excision of the 

 hind wings almost opposite the apex of cell M3 + Cui + Cu. 



Abdomen of male with three spines, p. 357 Scoliid/E 



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

 entiated 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 anterior 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 Ampidicidce 



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

 closed by the hypopygium. p. 370 Sphecid^e 



EE. Posterior metatarsi elongate and dilated. Some of the hairs, especially 

 of the thorax, plumose. A pollen-collecting brush or a corbicula present 

 in the majority of females. Maxillae usually with either the stipes or 

 the lacinia elongate; the latter often very long and covering the tongue; 

 the ocelli never distorted; the abdomen rarely petiolate, and never with 

 a petiole composed only of the first sternite. 

 F. Hind tibiae with apical spurs. If the marginal cell (2d Ri + R 2 ) is long 

 and slender, reaching nearly to the wing apex, the anal lobe is short 

 and fully separated. Cell M4 usually as large as cell 1st M 2 . 

 G. Females without a corbicula. First submarginal cell (R + 1st Ri) 

 rarely divided (by the base of R s ) in which case there is a large 

 anal lobe present. In case the marginal cell (2d Ri +R 2 ) is longer 

 than the three submarginals, taken together, there is usually a well- 

 marked anal lobe in the hind wings. 

 H. Wings with two submarginal cells (very rarely less). 



