MOUNTAIN ANTS OF NORTH AMERICA. 519 



straight, marginate occipital border, large eyes and ocelli and very 

 short cheeks. Mandibles small, with 5 or 6 teeth. Clypeus convex, 

 its border straight and entire in the middle. Antennae slender, scapes 

 as long as the first and second funicular joints together; joints of 

 club strongly constricted at their proximal ends so that this portion of 

 the antennae is moniliform. Mesonotum convex, distinctly longer 

 than broad; scutellum as long as broad; base of epinotum straight 

 in profile, gradually sloping to the posterior swellings which are feebly 

 developed, rounded above and angulate behind, but not pointed. 

 Nodes of petiole and postpetiole low and rounded. Legs slender. 



Mandibles subopaque, very finel,y and indistinctly striate; clypeus 

 smooth and shining; head subopaque, obscurely punctate-rugulose. 

 Remainder of body smooth and shining, except the posterior swellings 

 of the epinotum, which are subopaque and irregularly rugose. 



Pilosity much as in the worker, but the long, erect hairs on the 

 gaster finer. 



Piceous; clypeus and legs pale brown; head black; mandibles and 

 antennae sordid yellow. Wings as in the female, but a little more 

 whitish. 



Described from seventeen workers, one female and one male taken 

 by Dr. R. V. Chamberlin at East Mill Creek, Salt Lake County, Utah. 



This form is evidently quite distinct from any of our other North 

 American species of Aphaenogaster though most closely related to 

 subterranea. The worker and female of ui7ita can be distinguished 

 from the various forms of this species by their color, the greater length 

 of the scapes and funicular joints and the much larger eyes, the worker 

 by its more rectangular head, peculiar epinotum, more conical post- 

 petiole and larger gaster, the female by its smaller head, shorter epino- 

 tal spines and much darker pterostigma, the male by the very different 

 epinotum, longer mesonotum, more shining and much less densely 

 sculptured head and the paler body and appendages. 



68. Stenamma nearcticum Mayr. 



This species is known only from male and female specimens. What 

 Mayr took to be the worker belongs to brevicorne. The types were 

 from California. My collection contains a male and female from 

 Corvallis, Oregon. 



69. Stenamma brevicorne Mayr subsp. diecki Emery. 

 British Columbia: Yale, type locality (G. Dieck). 

 Illinois: Rockford (Wheeler). 



