A REMARKABLE NEW SPECIES OF PROCERATIUM, 
WITH DIETARY AND OTHER NOTES ON THE GENUS 
(HYMENOPTERA: FORMICIDAE) 1 
By William L. Brown, Jr. 
Department of Entomology 
Cornell University 
Ithaca, New York 14853 
Introduction 
The primary purpose of this paper is to describe an extraordinary 
new insect from Madagascar. This ant has, in effect, two tail ends, 
one of which, the false end, is a logical extension of the tendency in 
certain Proceratium species (e.g., P. pergandei and P. micromma- 
tum) for the second gastric segment to extend rearward, while the 
true gastric apex projects from its ventral aspect in an anterior 
direction. The adaptive reason for this down-and-forward orienta¬ 
tion of the true abdominal apex is not entirely understood, though it 
is clear that the deployment of the sting is usually an important 
feature of prey-attack in ponerine ants. 
Proceratium diplopyx new species 
Figs. 1, 2. 
Holotype worker: TL 6.0, HL (including clypeus) 1.44, HW 1.25, 
ML (beyond clypeus) 0.15, scape L 1.12, eye diameter0.12, WL 1.77, 
petiole L in side view 0.70, gaster L 1.97, hind tibia L 1.26, hind femur 
L 1.53 mm. Cl 87, SI 90. (A single paratype worker hardly differs 
from the holotype by more than the usual errors of measurement, 
except that the head is slightly wider: HW 1.29 mm. Cl 90.) 
Habitus well portrayed in figures 1 and 2. Figure 2 shows the head 
tilted slightly back from the full-face view plane, so that the posterior 
cephalic margin appears straight and is slightly surpassed by the 
scapes laid back in repose. In perfect full-face view, the center of the 
posterior margin is feebly concave, and the scape laid back does not 
‘A report of research from the Cornell University Agricultural Experiment Station, 
New York State College of Agriculture and Life Sciences. The research was supported 
in part by National Science Foundation Grant GB-31662 
Manuscript received by the editor February 14, 1980 
337 
