HETEROGYNA — MYRMICID^K. 99 



maxillary and labial palpi 2-jointed ; metathorax unarmed; head very 

 larj;e, siibquadr.ite, eniarginate posteriorly and divided above by a lon- 

 gitudinal impressed line Solenopsis Westw. 



Antennte ll-12-.jointed 5. 



5.— Petiole attached to upper basal surface of abdomen, which is cordate, de- 

 pressed above, convex beneath, acuminate posteriorly : antennse 11- 

 jointed ; metathorax usually armed with two sjiines or teeth, rarely 



unarmed Crematitoga^ter Lund. 



Petiole attached to basal middle of the abdomen 6. 



f). — First .joint of petiole nearly cubical, not or scarcely narrowed anteriorly: 

 apical margin of mandibles confusedly dentate, angular, so that when 

 they are closed there is a triangular space between them and the cl.v- 

 l)eus ; the latter short, with two longitudinal crests which are terminated 

 in front by two obtuse teeth ; antenna; 1'2-jointed, the club 3-jointed : 

 thorax not strangulated above ; metathoi-ax with two strong spines be- 

 hind and two very small teeth in front towards anterior margin : max- 

 illary i)ali)i 4-jointed, labial palpi IJ-jointed 9Iyrine«ina Curt. 



First joint of petiole narrow and cylindrical at base, nodose and elevated 



at ajtex 7. 



7. — Last three joints of funicle taken together distinctly shorter than the pre- 

 ceding joints combined — 8. 



Last three joints of funicle taken together as long or longer than the pre- 

 ceding joints combined 9. 



8.— Frontal area deep, obtusely rounded behind; maxillary palpi 4-5-jointed, 

 labial pali)i 3-jointed. 

 Thorax strangulated between nieso- and metathorax, the pro- and meso- 

 tborax together more or less hemispherical. ..Aphienogaster Mayr. 

 Thorax not con.stricted between meso- and metathorax. the sutures indis- 

 tinct, prothorax much broader than the rest of the thorax. 



Pogonoinyrinex IMayr. 

 Frontal area acute behind ; maxillary palpi 6-jointed, labial palpi l-joiuted ; 

 metathorax rather flattened above: femora claviform, tibial s])urs pec- 

 tinate Myrniica Latr. 



9.— Metathorax entirely unarmed ; thorax strongly constricted above between 

 meso- and metathorax. pro- and mesothorax without trace of suture 

 between them ; clvpeus longitudinally furrowed medially, its anterior 

 margin protuberant and produced beyond the mandibles, which are 

 rather narrow ; intenns 11-12-jointed, the club 3-jointed, of which the 

 last joint is as long or longer than the two preceding joints united. 



iVIonoinoriuin Mayr. 



Metathorax armed with two teeth or spines 10. 



10. —Funicle of antennse, which are 12-jointed. without distinct club, gradually 

 thickening from base to apex, first joint as long as broad, the others 

 beginning very short are gradually lengthened ; eyes very small ; man- 

 dibles broad, dentate; frontal area narrow and deep; thorax slightly 

 constricted between meso- and metathorax. the teeth of the latter tri- 

 angular, acute; first joint of petiole narrow and cylindrical at base, 

 nodiform at apex; maxillary palpi 4-jointed, labial palpi 3-jointed. 



Steuaninia \Ve.stw. 

 - - Funicle with a distinct club of :i joints ; eyes moderately large 11. 



