HYMENOPTERA. 647 
D. Vein V 3 arising at or beyond the end of the 2d cell III (Fig. 
773) * 
E. Petiole of abdomen cylindrical, smooth ; antennae slender 
at apex; tibiae of middle legs with two apical spurs, p. 650. 
SPHECIDiE. 
£E. Petiole of abdomen depressed and generally furrowed 
above ; antennae thickened at apex; middle tibiae with one 
apical spur. p. 655. Mimesid.e. 
DD. Vein V s arising before the end of the 2d cell III. 
MELLINIDiE.f 
CC. Base of abdomen without a long, slender portion (not 
petiolate). 
D. Veins V 2 and V 3 arising from the second submarginal cell 
(Ills) (Fig. 775); sometimes vein V a arises from the end of 
cell III,. 
E. Fore wings with an appendiculate cell (Fig. 775, ap.)\ 
mandibles usually more or less deeply notched on the ex¬ 
terior margin, p. 652... Larrid^e. 
EE. Appendiculate cell wanting; mandibles with the ex¬ 
terior margin entire. 
F. Labrum short, projecting but little, if at all. p. 654. 
NyssonidjE. 
FF. Labrum distinctly exserted, sometimes forming a long 
triangular beak (Figs. 776,777) 652.Bembecid^e. 
DD. Vein V 2 arising from cell III 4 and vein V 3 from cell III, 
(Fig. 779). p. 654.. PHILANTHID.E. 
BB. Fore wings with two closed submarginal cells (Fig. 781, 2d 
III + III, and IIL). 
C. Prothorax long and narrow, produced anteriorly into a neck. 
(As this family includes only a single American species, and 
that a very rare one, it is not discussed in this work.) 
AMPULICIDjE. 
CC. Prothorax short, transverse, p. 655. PemphreI/ONIDjE. 
BBB. Fore wings with only one closed submarginal cell (Fig. 783, 
2d III + III,), p. 656. CRABRONIDiE. 
* Vein V* is the vein between cells V and 1st V 3 , and between cells V 3 
and 1st V a . In the species represented in Figure 773 it arises near the middle 
of cell III, and extends backward for more than half its length. 
f This family includes only two species found in the Rocky Mountain 
region, and a single, very rare, one found in the Eastern States. It is not 
discussed in this work. 
