LEPTOTHOEAX. 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-mesouotal 

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

 thorax slightly emai'ginate at the latter suture ; metanotum — the 

 basal portion rectaugidar, 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. 



2 . Closely resembles the ^ , very little larger ; metanotum 

 generally armed ; abdomen a little more massive ; fore wings \\itli 

 one cubital and one discoidal cell. 



d" . Eesembles the $ , the head smaller, the thorax shorter and 

 a little deeper; mandibles narrow, with the masticatory margin 

 truncate ; clypeus arched, convex; antennae 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. 



Ki'i/ to tlie Species. 



a. Thorax : the metanotum without teetli or 



spines L. inermis, p. 21-j. 



b. Thorax : the metanotum with either teeth or 



spines. 

 a . Lenirth over 3'5 mm. ; of a pale ochraceous 



yellow L. taylori, p. 216. 



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



dark brown. 



a-. Thorax sculptured and opaque ; meta- 



uotal spines distinct. 



a^. Meso-metanotal suture distinct ; meta- 



notal spines comparatively large and 



acute at apex ; colour ferruginous 



red L. rothnerji, p. 217. 



&\ Meso-metanotal suture nearly obsolete ; 

 metauotal spines comparatively small 

 and obtuse at apex ; colour blackish 



brown L. schnrri, p. 218, 



b-. Thorax shining, with only a few striae 



and irregular rugosities L.fultoni, j). 216. 



249. Leptothorax inermis, Fo)X'l, Bev. Suisse Zool. x (1902), p. 229. 



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

 antennae, 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 in 

 front as nosteriorlv, the sides of the head somewhat convex ; 



