LEPTOTHOBAX. 215 



long as, or longer than the rest of the flagellum ; eyes lateral, 

 comparatively large, oval. Thorax long and narrow, the pronotum 

 convex anteriorly and rounded at the sides in front ; pro-mesonotal 

 suture obsolete; meso-metanotal suture distinct, in profile the 

 thorax slightly emarginate at the latter suture ; metanotum the 

 basal portion rectangular, generally armed with two spines or teeth 

 at the posterior lateral angles (in some species entirely unarmed) 

 legs moderately long. Pedicel : the nodes rounded, the 1st node 

 shortly petiolate anteriorly ; abdomen elongate, oval. 



. Closely resembles the , very little larger ; metanotum 

 generally armed ; abdomen a little more massive ; fore wings with 

 one cubital and one discoidal cell. 



S . Eesembles the $ , the head smaller, the thorax shorter and 

 a little deeper; mandibles narrow, with the masticatory margin 

 truncate ; clypeus arched, convex ; antennse 13-jointed. Thorax : 

 the mesonotum convex, the disc marked with two posteriorly con- 

 vergent impressed lines. Pedicel as in the $ ; the abdomen 

 smaller, broadly oval. 



Key to the Species. 



a. Thorax: the metanotum without teeth or 



spines L. inermis, p. 215. 



b. Thorax : the metanotum with either teeth or 



Tes. 

 n<rth over 3'5 mm. ; of a pale ochraceous 



yellow L- taylori, p. 216. 



b'. Length under 3*5 mm. ; chestnut-brown to 



dark brown. 

 a 2 . Thorax sculptured and opaque ; meta- 



notal spines distinct. 



a 3 . Meso-metanotal suture distinct ; meta- 

 notal spines comparatively large and 

 acute at apex; colour ferruginous 



red L. rothneyi, p. 217. 



b 3 . Meso-metanotal suture nearly obsolete ; 

 metanotal spines comparatively small 

 and obtuse at apex ; colour blackish 



brown L. schurri, p. 218. 



6 2 . Thorax shining, with only a few striae 



and irregular rugosities L.fultom, p. 216. 



249. Leptothorax inermis, Forel, Rev. Suisse Zool. x (1902), p. 229. 



3 . Head and thorax dark brown, almost black ; mandibles, 

 antenna, legs and pedicel chestnut-brown, abdomen dark chestnut- 

 brown; head and thorax shining, very slightly longitudinally 

 rugose, taking in certain lights the appearance of being widely 

 striate ; the legs, pedicel and abdomen smooth, highly polished and 

 shining ; pilosity almost entirely wanting, reduced to a few very 

 scattered hairs ;" pubescence on the scape of the antennae and the 

 tibiae recumbent. Head a little longer than broad and as broad m 

 front as posteriorly, the sides of the head somewhat ( 



