MEXICAN FORMICID^. 869 



cuated in front. Mandibles robust and armed with seven 

 acute teeth. Antenna rather short, the scape stout, not 

 reaching to the occiput; the two basal joints and the last 

 joint of the flagellum longest, joints three and four slightly 

 longer than wide, the remaining joints about as long as 

 wide and increasing gradually in width towards the end 

 of the antennae. Prothorax about one -fourth narrower 

 than the head, widest in front of the middle and very 

 convex; pro-mesonotal suture rather deep; the mesono- 

 tum distinctly elevated and convex; metanotum not ele- 

 vated, convex and with a transverse impression each side 

 near the anterior margin. Scale stout, nearly as broad 

 above as below, the apex bluntly rounded. Abdomen 

 broadly ovate and about as long as the thorax. Legs 

 stout. 



Polished. Head and thorax extremely fine and densely 

 punctured, the punctures slightly stronger on the clypeus. 

 Mandibles finely but rather indistinctly striated and finely 

 and densely punctured, intermixed with few coarser punc- 

 tures. Abdomen finely shagreened. 



Erect hairs yellowish, sparse and almost wanting on 

 the abdomen, most numerous on the head in front of the 

 antenna and mandibles, the thorax and around the end 

 of the abdomen; antennse and legs without erect hairs, 

 except a few at the apex of the scape. Appressed pu- 

 bescence whitish and dense. 



Color lighter or darker brown, the thorax, legs and ab- 

 domen sometimes quite pale yellowish. Mandibles red- 

 dish-brown, the teeth and eyes black. Clypeus, the scape 

 along its front edge, declivity of the metanotum, the base 

 and sutures of the abdomen and the legs more or less dis- 

 tinctly yellow or brownish-yellow. 



Small worker: Length, about 3.4 mm. Resembles in 

 every respect the large worker, except that the head is 



