454 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
this run circular tunnels, which vary in number, from one to eight. 
From the entrance the tunnel runs perpendicularly to the first fungus- 
garden chamber. This is about three inches in diameter and from 
six inches to two feet below the surface. The colonies are rather 
small. Although on the watch for inquilinous insects I failed to find 
any spiders in the turrets, as reported by Emery (Ann. Soc. ent. 
France, 1888, ser. p. 66.) in nests at Caracas. 
142. Acromyrmex (Acromyrmex) coronata (Fabricius). 
Several colonies were found at Para. 
143. Acromyrmex (Acromyrmex) aspersa (F. Smith). 
Common at Natal, Baixa Verde. 
144. Acromyrmex (Acromyrmex) octospinosa (Reich). 
Numerous workers were found at Itacoatiara. 
145. Acromyrmex (Acromyrmex) nigrosetosa Forel. 
One colony was found at Souza, near Para. 
146. Acromyrmex (Acromyrmex) nigra (F. Smith). 
Several workers are in the collection from Itacoatiara. 
147. Acromyrmex (Acromyrmex) emiliae Forel. 
A few workers were found at Madeira-Mamoré Camp 39. 
This large, opaque form is very distinct from the related species 
in having no tubercles on the epinotum. 
148. Trachymyrmex diversus, sp. nov. 
Worker. Length 4 mm. 
Head, excluding mandibles, a little longer than broad, broader 
behind than in front, with convex sides, and pointed posterior corners; 
occipital margin slightly concave. Eyes convex, located in front of 
