380 bulletin: museum of comparative zoology. 



erably in stature but only feebly polymorphic. Their mandibles 

 have a broad, dentate apical border. The maxillary palpi are 6- 

 jointed, very rarely 5-jointed, the fourth joint not longer or but 

 slightly longer than the fifth; the labial palpi are 4-jointed. The 

 clypeus is trapezoidal and usually distinctly carinate; the clypeal and 

 antennal foveae are confluent. The frontal area is usually very dis- 

 tinct; the frontal carinae are subparallel or diverging behind. The 

 eyes are convex, moderately large, and situated behind the median 

 transverse axis of the head. The ocelli are always distinct. The 

 antennae are 12-jointed and inserted near the posterior corners of the 

 clypeus; their funiculi are more or less thickened apically but without 

 a club. The thorax is distinctly and often deeply constricted in the 

 mesoepinotal region. The epinotum is angular or rounded in profile 

 and always unarmed. The petiole is scale-like, erect and compressed 

 anteroposteriorly. 



The female is usually considerably larger than the worker, but in 

 some parasitic species, of the same size or even smaller than the larg- 

 est worker forms. The anterior wings have a discoidal and a single 

 closed cubital cell. 



The male is always larger than the worker and usually slightly 

 smaller than the female. The mandibles are narrow, flat, and pointed, 

 with short, dentate or edentate apical border. The frontal carinae 

 are very short or vestigial ; the antennal scapes long, the first funicular 

 joint longer than the second. The petiole is thicker and less com- 

 pressed anteroposteriorly than in the worker and female. The 

 genitalia are robust and conspicuous, their stipes simple, without 

 an appendage; the subgenital plate is simple or feebly lobed. The 

 cerci are well developed, 



Ruzsky ^ was the first to divide the genus Formica into subgenera 

 by basing a subgenus, Proformica, on the Palaearctic F. nasuta 

 Nylander. He also included F. aberrant in the same group. All the 

 other species he referred to the subgenus Formica sens. sir. More 

 recently several additional Palaearctic species of Proformica have been 

 brought to light by Emery and Forel. As now defined, the group is 

 based mainly on the greater length of the first funicular joint of the 

 worker and female and of the genital stipes of the male. But the 

 group is, on the whole, rather vague, for the recently discovered 

 Tunisian Proformica cmmae Forel has close affinities with Catagly- 

 phis (Myrmecocystus olim), and our North American F. neogagates, 



' The ant fauna of the Kirghiz Stepps. (In Russian). Horae Soc. ent. Ross., 

 1903, 36, p. 294-316). 



