104 GENERA OF HYMENOPTERA. 



Dorymyrmex Mnyr.— 9 . MandihloH triaiiKnlar. externa) raarcin l)ri>a<lly 

 curved, itpicu] (or liitin^i margin dentate, with a large tooth in front; maxillary 

 palpi 0-jointed, joints 1-2 very short, 3 very long, curved, thickened toward ajiex ; 

 labial palpi 4-jointed ; dypeus triangular, slightly projecting between insertion 

 of antennje, not carinate, posterior angles rounded ; clypeal an.^ antennal loveje 

 confluent; frontal carinie short, linear, panillel, slightly diverging behind; an- 

 tennse r2-jointed. inserted at the margin of the (■lyi)eus, s«ii)e long, slender, 

 funicle filiform, the joints fnmi base to apex of the latter gradually shorter, basal 

 joint very long, the penultimate very short; frontal area subtriangular ; eyes 

 ovate, placed in the superior part of the head nearly equidistant from the ante- 

 rior and i»osterior margins ; ocelli distinct ; occiput deeply arcuately excavate, the 

 lateml margins slightly curved, the head beneath with a circle of long hairs; 

 thorax constricted between nieso- and metathoi-ax, the latter arched above, armed 

 with a tooth or obtuse horn ; abdomen, seen from above, with four segments, 

 anus inferior, the petiole either with a node or scale ; legs slender, spurs of pos- 

 terior tibite with long pectinations. 



9-— Head oval, convex above, excavated beneath, very broad behind the mid- 

 dle; clypeus transversely triangular, j)rojecting- between insertion of antennae, 

 convex medially ; frontal area acutely triangular : frontal groove short and dis- 

 tinct ; antennie 12-jointed ; thorax compressed ; metathorax unarmed ; abdomen 

 elongate oval, the scale of the one-jointed petiole erect, ovate, obtusel.v toothed 

 above; wings with two submarginal cells; tibial spurs pectinate. 



%. — Mandibles moderately long, apical (or bitingt margin multidentate, the 

 apex very acute ; clypeus transversely triangular, projectiu" slightly between the 

 insertion of antennse; modei-ately convex; antennse 13-j ited, the two basal 

 joints of funicle longer than the remainder; mesothorax produced above the 

 prothorax ; metathorax unarmed; abdomen oval, the petiole above subnodose; 

 legs very slender, tibial .spurs pectinate ; external genital valves compressed, sub- 

 linear, rounded at tip. 



This genus, and also the preceding, belong to the Formicidfe, and 

 are placed by Dr. Mayr between Prenolepia and Liometopum. 



IjObopelta Mayr.— g . Mandibles flat. depres.sed, slender, triangular or 

 parallel-margined, obliquely truncate at tip so that the truncation is the "biting 

 edge," which is toothed; clypeus elevated medially, kite-shaped and carinate, 

 the carina extending posteriorly between the clo.sely i)laeed frontal ridges ; the 

 anterior middle of the clypeus is obtuse or sharply prolonged and fills up the 

 triangular space left by the mandibles ; antennse 1'2-jointed, the scape long, reach- 

 ing beyond the occiput, first joint of flagellum as long or longer than the second ; 

 eyes moderately large and rounded ; thorax feebly convex above, subcompressed 

 laterally, prothorax much narrowed anteriorly, mesothorax very short, only one- 

 third as long as the prothorax and indistinctly separated from the metathorax, 

 the face of which is more or less abruptly declivous; abdomen long, cylindrical, 

 scale of the petiole sometimes compressed laterally, longer than broad, or the 

 length and breadth are subequal, or it is very strongly compressed from before 

 and behind and transverse ; tarsal claws pectinate. 



This genus belongs to the Poneridte, and is represented in our 

 fauna by one species {septentrmialis Mayr), found near Washington, 

 D. C. 



