2. Compound eye represented by only one facet or 
absent (subfamily Ecitoninae) .............. 6 
Compound eye represented by more than a single 
rem Ciera LOA Nt yi Ne xo. ake 3 
3. Head oblong in face view, with large, smooth eyes 
(Fig. 11); antennae always close together at 
base, scape little more than half length of head 
(Fig. 11) ; medium-sized to large ants of wasp- 
like appearance (subfamily Pseudomyrmecinae) 
Re re tN lo oh ae fale ne 20 
Head shorter, eyes no larger than in Fig. 13; bases 
of antennae frequently well separated; scape 
usually longer, frequently longer than head (Fig. 
3) (subfamily Myrmecinae) 
4, Genital opening small and circular, surrounded 
by stiff hairs forming a terminal nozzle (Fie.6C 
and D) (subfamily Formicinae) ........... 13 
Genital opening slitlike or inconspicuous (Figen / GC) 
Ehret ss Sie be Sonus ek kn ko na on 5 
9. Gaster with a distinct constriction between first and 
second segments; abdomen with a well-devel- 
oped sting that is frequently retracted and not 
visible externally (Fig. 7C) (subfamily Ponerin- 
A oe a ea 7 
Gaster without a constriction between first and 
second segments (Fig. 84—D) ; abdomen without 
a sting (subfamily Dolichoderinae) ......... 10 
Subfamily ECITONINAE 
6. Tarsal claw toothed (Fig. 174) ....... 1. Labidus 
Tarsal claw without a tooth (Fig. 17B) 
oes Pele. s UR be 2. Neivamyrmex 
Subfamily PONERINAE 
7. Scale of petiole upright, rectangular (Fig. 12B) ..8 
Scale of petiole ovoid, rounded (Piget2 © ones 9 
11 
8. Second segment of abdomen unusually large (Fig. 
Pa Oa a ae ee eee Oe. 5. Proceratium 
Second segment of abdomen of normal size (Fig. 
ts BUR ee pe I cs 2 Re TN 4. Ponera 
9. Mandibles with enlarged teeth (Fig. 124) ; second 
segment of abdomen of normal size (Fig. 7H) 
Ser er Wa ae ai a ee eed 3. Amblyopone 
Mandibles without enlarged teeth; second segment 
of abdomen unusually large (hice, C) 
ee ene ne ae MeN Sr as ene 6. Sysphincta 
Subfamily DOLICHODERINAE 
10. Epinotum with a flat, dorsal projection extending 
posteriorly and forming an overhang in lateral 
views (Figw! 3A) so ae ai 7. Dolichoderus 
Epinotum without a dorsal projection (Fig. 13B) 
CES cM er gag See AEA UG ey) So Al 11 
CTE RO a Oe ga eae 8. Dorymyrmex 
Maxillary palp with segment 3 much shorter than 
segments 4-6 combined .................. 12 
12. Node of petiole vestigial (Fig. 8A) .. 10. Tapinoma 
Mandibles stouter and toothed (Hien 4B eae) 
Bs OPO ar eae ee 12. Acanthomyops 
Maxillary palp with five or six segments ....... 16 
Fig? 15.—Diagnostic parts of 
queen ants of the subfamily Myr- 
mecinae. A, Trachymyrmex, tan- 
gential view of head; B, Lepto- 
thorax, side view of head; C, Ste- 
namma, side view of head; D, 
Pheidole, dorsal view of petiole; E, 
Leptothorax, dorsal view of petiole; 
F, Tetramorium, side view of head; 
G, Pheidole, side view of head. 
