1967] 
Brown — Pheidole 
337 
wide, the sides produced as narrowly rounded angles, but not strictly 
speaking as conules. 
Gaster of the highly modified form shown in Figs. 6 and 7. The 
truncate portion involves large parts of the first 4 tergites, which in 
the living, unswollen gaster fit together to produce a nearly flat cir- 
cular disc surrounded by a heavy raised ridge that is continuous ex- 
cept for a small sector at the edge of the fourth segment. This disc 
is weakly shining, finely reticulate and with numerous very small, 
spaced tubercles with smooth, rounded heads; and also with small, 
curved, appressed pennant-shaped hairs. 
Dorsum of head finely reticulopunctulate, with overlying costula- 
tion (striation) as shown in Figs. 5 and 7. Frontal area, middle of 
clypeus, upper surfaces of mandibles, “occipital” surface and a large 
area above and behind the compound eyes, extending to the ventral 
surface of the head, smooth and shining. The smooth areas of the 
back and sides of the cranium coincide almost exactly with the dark 
brown pigment pattern as shown in Figs. 5 and 7. Antennal scapes 
finely punctulate, shining, on apical halves. Alitrunk and legs pre- 
dominantly smooth and shining, except for these striate to punctate- 
striolate areas: sides of pronoum (steeply oblique), anterior surface 
and lateral margins of scutum (horizontal, paralleling margins), 
sides of propodeum (prevailingly longitudinal, as shown in Fig. 7). 
Petiole and postpetiole finely and densely punctulate, opaque, ex- 
cept for upper anterior surface of petiole, which is almost smooth 
and definitely shining. Base of gaster punctulate-striate, with radiat- 
ing costulae, passing behind into a smooth, shining dorsal surface (in 
front of the truncate portion) and finely reticulate, shining sides; 
ventral base of gaster sculptured like the tergal base, but passing 
into shining, smooth and reticulate areas caudad. 
Paratype female (dealate) from collection M-60, not measured, but 
nearly the same size as the queen of the type nest, described above. 
The scape bases of the paratype are thicker, and originally carried 
more of the whitish gelatinous substance. 
Holotype soldier (Museum of Comparative Zoology, Harvard 
University, Cambridge, Massachusetts, USA) taken together with 
queen, other soldiers, workers and brood, from a small colony (M-77) 
nesting in rotten wood on the rain forest floor near the Igarape 
Marianil, which is a small creek just beyond Kilometer 5 on the Rio 
Branco Road after its branching from Amazonas Ruta 1 (“Itacoatiara 
Highway”). The road fork is 19 km NE of Manaus, and the 
igarape is about 24 km NE of Manaus by road. This forest is on 
