1923 ] 
Two New Ants from Bolivia 
17 
Legs long, rather slender, tibial spines coarse, those on posterior 
pair strongly pectinate. 
(Fig. 2. Female Probolomyrmex? boliviensts sp. nov. A, profile view; B, head, dorsal view) 
Opaque, finely, densely reticulate and in addition with 
rather coarse, foveolate punctures, especially prominent on the 
front of head, epinotum and gaster. Pubescence white, very 
fine, closely appressed, moderately abundant, more so on gaster 
and appendages. 
Brownish red, appendages brownish yellow. 
Type-locality . — Rurrenabaque, Bolivia. 
Type.— Cat. No. 25906, U. S. N. M. 
Described from a unique female found beneath a stone, 
near a small colony of Ponera sp. 
In Probolomyrmex holiviensis the posterior segments of the 
gaster are much smaller, the antero-ventral petiolar spine is 
rounded and points forward and the epinotum is dentate rather 
than angulate, characters different from those in P. filiformis 
Mayr, but I can find no difference of generic value that would 
separate the two. In the worker of filiformis Mayr the posterior 
gastric segments are larger, the antero-ventral petiolar spine is 
lamellate and "directed backward and the epinotum is angulate, 
instead of dentate. Perhaps when the female oi filiformis or the 
