254 
Psyche 
[December 
female — Exactly 6 antennal segments, of which the third and fourth 
are very short and the first (scape) and sixth (apical) are very long 
(Figs. 1-4) ; mandibles long and linear, straight or bowed, more than 
1/3 as long as the head proper, with an apical fork of two prominent 
teeth, other teeth absent to few, usually separated (Figs. 1-4, 7-16) ,* 
occiput with a deep median posterior excision between two broad, 
rounded lobes, head in front distinctly narrowed (Figs. 1-4) ; spongi- 
form appendages, or at least their vestiges, present on petiole and 
postpetiole (Figs. 5, 6) ; head and often most of alitrunk reticulate- 
punctulate and opaque, rarely with superimposed rugulation. Males 
are not dealt with here, since few of them are known, and they cannot 
be separated as a group from a number of other dacetine genera. 
Measurements, and the proportions derived from them, are very 
important in dacetine taxonomy, so it is necessary to measure with a 
high degree of accuracy. Measurements should be made to the nearest 
hundredth of a millimeter at least. A stereomicroscope magnifying at 
least 90X is required, plus a carefully calibrated reticule of the ocular 
squared disc type having finer subdivisions in one or more of the 
squares. The art of measuring dacetines is discussed at length else- 
where (Brown, 1953d: 7-15), so I shall repeat here just the essentials 
for use with this paper. 
Head length (HL), maximum measureable length of head proper 
as seen from dorsal full-face view, including all of clypeus and occipi- 
tal lobes. 
Head width ( HW) is the maximum width of the cranium measured 
in the same view as for HL. 
Mandible length (ML), exposed length of mandibles, including 
apical teeth, measured in same view from which HL is obtained. 
Weber’s length (WL), oblique length of alitrunk from side view, 
measuring from base of anterior pronotal declivity to metasternal 
extremity. 
Total length (TL) of the body is the summed lengths of ML, HL, 
WL plus the axial lengths of petiole, postpetiole and gaster measured 
separately. 
Cephalic index (Cl), head width expressed as a percentage of head 
length, or HW/HL X 100. 
Mandibulo-cephalic index (MI), ML/HL X 100. 
In addition to the dichotomous key to the species, I have constructed 
a table giving known ranges of values for the seven quantitative 
characters most used in species-level taxonomy of the genus. This 
table may be used either as a primary key or as a check on the deter- 
minations made with the dichotomous key. Number of individuals 
