24S PROCEEDINGS OF THE ACADEMY OF [Feb., 



with three slender longitudinal carina?. Antenna? 12-jointed, first 

 fiuiicular joint longer than the three succeeding joints together; 

 remaining joints shorter than broad; two basal joints of club siibequal. 

 Thorax not impressed at the mesoepinotal suture. Epinotal spines 

 short, rather acute, ol^liquely erect. Petiole thickened behind, node 

 subconical, obtuse. Postpetiole much larger than the petiole, sub- 

 globose. 



Mandibles striated. Clypeus shining. Head, thorax and pe tiole 

 subopaque. punctate and finel}' rugose, pronotum more shining in the 

 middle. 



Hairs on the body clavate, on the legs and antennal scape non- 

 clavate and sparse. 



Fuscous black; mandibles, articulations of legs and the tarsi reddish. 



Type locality: Hill City. S. Dak. (Pergande). 



Descriljed from a single specimen in the collection of Prof. C. Emery. 

 14. Leptothorax neomexicanus sp. nov. 



Worker (PI. XII, fig. 18).— Length 2.25-2.5 mm. 



Head longer than broad. Mandibles 5-toothed. Ch-peus mod- 

 erately convex, broadly rounded in front, not impressed, Antennte 

 slender, 12-jointed; scape extending to a distance equal to its own 

 breadth beyond the posterior angle of the head ; funiculus terminating 

 in a 3-jointed club, the two basal joints of which are subequal and 

 together shorter than the terminal joint ; first funicular joint as long as 

 the three succeeding joints together; joints 2-8 of the funiculus as 

 long as broad. Thorax not much broader in front and above than 

 behind and below; humeral angles rounded; dorsal surface flattened, 

 without mesoepinotal suture or constriction. Epinotal spines short, 

 robust, blunt, not longer than broad at their bases and nearly twice as 

 far apart at their bases as long. They are directed obliquely upward, 

 outward and backward. Petiole hardly 1^- times as long as broad; 

 distinctly wider behind than in front, sides somewhat convex; in profile 

 the node is nearly as high as the length of the petiole, its anterior slope 

 steep, slightly concave; the summit somewhat truncated, passing 

 abruptly into the angular posterior declivity ; ventral surface in front 

 with a prominent tooth, directed downward and forward. Postpetiole 

 nearly twice as broad as the petiole; nearly as long as broad, sub- 

 globular, its anterior dorsal surface in profile abruptly convex, the 

 posterior dorsal surface more flattened. Gaster of the usual shape 

 with slight basal angles. 



Mandibles coarsely striated and punctate. Clypeus longitudinally 

 rugose, especially on the sides, behintl without rugie, smooth and 



