26 o 
Psyche 
[December 
tergite smooth and shining (Fig. 8; Argentina, se. Brazil) 
hindenburgi Forel 
Dorsal scrobe borders merely narrowly cariniform, not lamellate ; 
mandibles without preapical dentical proximad of preapical tooth ; 
basal costulae of gastric dorsum extended over basal third or 
more of first tergite as fine, sericeous-opaque striolation (Fig. 4; 
C. America to s. Mexico; Bahamas) lanuginosa Wheeler 
18. Head with a strong concavity anterior to each eye, and thus 
appearing constricted in full-face view (Fig. 7) ; humeral tuber- 
cles large and produced (mandibles broad, contiguous or nearly 
so when closed, each with a single short, broad preapical tooth; 
Fig. 7) (Panama; hylaean S. America to Bolivia) 
precava Brown 
Head parallel-sided or gently tapered in front of eyes, without 
marked preocular concavities; humeral tubercles or angles small, 
not produced (mandibles slender, not contiguous at full closure, 
preapical dentition diverse, but not as above) 19. 
19. Smaller species, with mandibles < 0.42 mm long; head broader 
(Cl > 75 ); ; _ 20. 
Larger species, with longer mandibles (ML > 0.42 mm) ; head 
narrow (Cl 75 or less) 21. 
20. Inner mandibular margin with a minute denticle near the apical 
third in addition to the preapical tooth ; head distinctly longitudi- 
nally rugulose (s. Mexico, Honduras) emeryi Mann 
Mandible with a single preapical tooth and no additional denticles 
proximad of this (Fig. 3) ; head at most weakly and indistinctly 
rugulose above (Costa Rica) nevermanni Brown 
21. Mandible with a small preapical tooth or denticle and, near it 
proximally, an additional minute denticle (Fig. 13; Costa Rica, 
Panama) rnicretes Brown 
Mandible with no teeth or denticles, or with a single minute 
preapical denticle (Fig. 2; Panama) lacacoca Brown 
(A population from Boquete, Chiriqui Prov., Panama, has 1 or 
2 preapical denticles on the inner mandibular border, and is thus 
intermediate between rnicretes and lacacoca , but this population 
is also distinctive in having the promesonotum coarsely longitudi- 
nally striate. The specimens are also larger. Possibly rnicretes 
lacacoca and the Boquete sample are simply local variants of a 
single unusually variable species, or perhaps three distinct species 
are represented here.) 
22. Inner mandibular border extended as a straight-edged lamella 
that terminates abruptly and subangularly at its distal end near 
