MANN: THE ANTS OF BRAZIL. 445 



the epinotum unarmed. Monomoriwn 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. Megaloviyrviex bituberculatus Forel. 



Many workers which agree closely with specimens from the Rio 

 Purus, received from Forel, were taken at Manaos, Porto Velho, and 

 Madeira-Mamore 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 umUacei, 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 

 cai'inae 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. 



