230 PROCEEDINGS OF THE ACADEMY OF [Feb., 



5. Leptothorax Emersoni Wheeler. 



L. Emersoni Wheeler, Am. Natural., XXXV, 1901, pp. 433-436. 5(j^$ . 



Worher (PL XII, fig. 6).— Length 2.5-3.3 mm. 



Head rather convex above, exchiding the mandibles not much longer 

 than broad, sides rounded, posterior margin very faintly excised in 

 the middle. Eyes rather large, convex, in the middle of the lateral 

 surface of the head. Ocelli often present. Clypeus large, convex, 

 broadly rounded in front. Mandibles 6-toothed. Antennae 1 1-jointed, 

 scape reaching nearly to the posterior angle of the head; first 

 funicular joint but little longer than the second and third joints 

 together ; terminal joint not quite as long as joints 7-9 of the funiculus. 

 Thorax rather long, rounded in front, narrowed behind, with distinct 

 promesonotal and mesoepinotal sutures, the thorax distinctly con- 

 stricted at the latter. Epinotal spines short, blunt, compressed, 

 hardly longer than broad at their bases, directed somewhat upward 

 and backward, their distance apart at the base greater than their 

 length. Petiole from above oblong, 1^ tnnes as long as broad, sides 

 slightly convex just in front of the middle ; in profile the node is pointed, 

 with distinctly concave anterior and posterior slopes. In some speci- 

 mens, however, the posterior slope is straight or even somewhat con- 

 vex. Ventral portion compressed, produced forward as a blunt projec- 

 tion. Postpetiole campanulate, wdth evenly convex dorsal surface; 

 seen from above it is nearly twice as broad as the petiole, its anterior 

 portion evenly rounded, not angulate. Gaster rather large, of the 

 usual shape, without distinct anterior angles. 



Head opaque. Mandibles coarsely punctate. Clypeus smooth in 

 the middle, with a few longitudinal ruga on either side. Head tra- 

 versed by coarse longitudinal and occasionally anastomosing rugse; 

 interrugal spaces coarsely and more or less confluently foveolate- 

 punctate. Around the eyes the rugse become more reticulate, though 

 they still have a distinctly longitudinal trend on the cheeks and lower 

 surface of the head. Thorax opaque, its dorsal surface reseml^ling 

 the head in sculpture, except that the rugse are more reticulate and 

 without longitudinal trend. On the pleurse the rugse become indis- 

 tinct and are replaced by even and closely aggregated foveolse. Petiole 

 opaque, sculptured like the pleurse. Postpetiole smooth and shining 

 above, delicately reticulate under a high magnification, especially on 

 the sides. Gaster very glabrous and shining. 



Whole body, including the legs and antennae, abundantly beset with 

 rather long, suberect, whitish hairs, which on the trunk are obtuse but 

 by no means clavate. Hairs on the gaster longest and most regularly 

 arranged. 



