STIGMATOMMA. 37 



posterior face ; abdomen narrow, not wider than the thorax, the 

 constriction between the basal two segments deep, giving the basal 

 segment a nodiform appearance ; sting exserted. 



This genus is closely allied to Amblyopone, Erichs., but differs 

 chiefly in the shape and armature of the mandibles. Next to 

 nothing is known of the habits of the species, of which three are 

 found within our limits. The nest is subterranean, and the $ and 

 <$ are winged. 



Key to the Species. 



a. Eyes comparatively large ; flagellum of an- 



tennae long, nearly half as long again as man- 

 dibles .' S. rotlmeyi, p. 37. 



b. Eyes smaller ; flagellum of antennae shorter, about 



^ual in length to mandibles. 

 J osterior lateral angles of head prominent. 



Length under 7 mm S.feae, p. 38. 



b'. Posterior lateral angles of head not pro- 

 minent. Length over 7 mm & belli, p. 38. 



41. Stigmatomma rotlmeyi, Forel (Amblyopone), Jour. Bomb. N. H. 

 Soc. xiii (1900), pp. 55 & 56, . 



. Black, the mandibles, the antennae and antenna! carinae, the 

 legs, and, obscurely, the apices of the abdominal segments, ferru- 

 ginous. Head, thorax and abdomen finely and densely punctured, 

 covered with short erect pale hairs, somewhat more dense and 

 longer on the femora and tibiae of the legs ; head and thorax opaque, 

 abdomen slightly shining. Head moderately convex above and on 

 the sides, almost as broad posteriorly as in front, the posterior 



Fig. 2(5. Stigmatomma rotJincyi, 



lateral angles rounded ; mandibles obliquely striate, the apex 

 smooth and polished, anterior margin of civ pens transverse, not 

 denticulate ; anteunal carinae short, wide apart ; joints of the 

 flagellum of the antennae rounded, distinct. Thorax : the prouotum 

 long, convex above ; the mesonotum depressed ; the metanotum 

 about as long as the pronotum, rounded above and broadening 



