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 
mesoépinotal 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. aberrans in the same group. All the 
other species he referred to the subgenus Formica sens. str. 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 emmae Forel has close affinities with Catagly- 
phis (Myrmecocystus olim), and our North American F. neogagates, 
1The ant fauna of the Kirghiz Stepps. (In Russian). MHorae Soc. ent. Ross., 
1903, 36, p. 294-316). ' 
