MANN: THE ANTS OF BRAZIL. 445 
the epinotum unarmed. Monomoriwm subterraneum is very different 
from any other of the American Monomoriums on account of these 
characters, and also because it is an unusually large species, with 
considerable variation in size between the largest and smallest workers. 
The small eyes, the abundant stiff hairs with which the body is covered, 
and the color, as well as the location in which the colony was found, 
indicate that this species is hypogaeic in habit. 
109. Megalomyrmex bituberculatus Forel. 
Many workers which agree closely with specimens from the Rio 
Purus, received from Forel, were taken at Manaos, Porto Velho, and 
Madeira-Mamoré Camps 39 and 41. This form, which is confined 
to the upper Amazonian region, attends Membracidae and the workers 
were generally found in company with these on shrubs in the deep 
forest. The nest is subterranean, the entrance nearly always at the 
base of a tree. The living insect is slow in its movements. 
110. Megalomyrmex wallacei, sp. nov. 
Plate 3, fig. 28. 
Worker. (Plate 3, figs. 28). Length 5 mm. 
Head, excluding mandibles, one and a third times as long as broad, 
broadest at clypeus, strongly narrowed above eyes, with slightly 
convex sides and straight occipital border, the latter distinctly, 
though narrowly, margined. Clypeus long and narrow, not separated 
from frontal area, the sides extending to outer bases of mandibles; 
anterior border projecting and narrowly rounded at middle. Frontal 
carinae distinct, elevated at insertion of antennae, parallel, extending 
to opposite anterior border of eye. Mandibles long and acuminate, 
the blade with four pointed teeth. Eyes large and very convex, 
situated at sides .of front of head, a little anterior to the middle. 
Antennae long and slender; extending about one third their length 
beyond the occipital corners. First funicular joint nearly twice as 
long as the second, joints 2-8 subequal, longer than broad, cylindrical, 
joints 9 and 10 subequal, each twice as long as the eighth and a little 
shorter than the apical. Thorax long and slender. Prothorax 
slightly rounded above, sides rounded. Promesonotal suture faint. 
