MOUNTAIN ANTS OF NORTH AMERICA. 505 



Worker. Length 3.3— i mm. 



Small; antennal scapes geniculately bent at the base and at the 

 flexure with a small rounded lobe, appearing as an acute tooth when 

 the scape is seen from the side. Frontal area very distinct, triangular. 

 Frontal carinae large, lobular. Epinotal spines slightly shorter than 

 the base of the epinotum, as long as their distance apart at the base, 

 rather slender, distinctly curved downwards at their tips. Petiole 

 in profile blunt and rounded above. 



Head, thorax and pedicel very coarsely and in the main longitudi- 

 nally rugose, the surface subopaque; frontal area opaque, finely and 

 densely longitudinally rugulose; concavity of epinotum smooth and 

 shining like the gaster. 



Hairs rather long, abundant and suberect on the body and legs as 

 in the typical schencki var. evierijana Forel. 



Head and gaster black; mandibles, antennae, thorax, petiole and 

 post-petiole deep brownish red; legs slightly more yellowish red. 



Female (dealated). Length 4.5-5 mm. 



Very similar to the worker; pronotum transversely, mesonotum and 

 scutellum strongly, pleurae more feebly longitudinally rugose; petiole 

 and postpetiole longitudinally rugose above, densely and finely punc- 

 tate on the sides and below as in the worker. Color like that of the 

 worker, except that the thoracic dorsum and some spots on the pleurae 

 are black. 



Male. Length 3.5^ mm. 



Antennae very short, the scapes especially, which are feebly bent at 

 the base and not more than three times as long as broad and shorter 

 than the three basal funicular joints together; club 4-jointed. Frontal 

 area large, distinct, triangular. Sculpture and pilosity much as in the 

 var. evieryana. Color dark piceous brown; head black; mandibles, 

 tarsi and articulations of legs brownish yellow; palpi whitish. Wings 

 pale hyaline throughout, not infuscated at the base as in emeryana. 



Described from numerous workers, several males and two females 

 from several localities about Lake Tahoe (Tallac, Angora Lake, Glen 

 Alpine Springs, Fallen Leaf Lake). The colonies are small and nest 

 under stones in shady places. 



21. Myrmica scahrinodis subsp. schencki var. inonticola var. noA'. 



Worker. Length 3-3.5 mm. 



Differing from the vars. emeryana and .iahoensis in its smaller size, 

 in color and in the shape of the antennal scapes, which are rectangu- 

 larly bent at the base and furnished at the flexure with a large, rounded, 



