350 S. B. Buckley on North American Formicidx. 



occiput not emarginate. Head oval above, and concave beneath the 

 occiput and back of the nientum to nearly the middle of the head ; 

 mandibles small, dark-brown, smooth, sub-triangular, curved inwards, 

 and sharp-pointed ; eyes circular, small, black, lateral, and about mid- 

 way of the head ; antennae filiform, and inserted in front near the base 

 of the mandibles; thorax slender; prothorax about half the width of 

 the head, rounded above and in front ; mesothorax small, depressed, 

 rounded above, with a strangulation between it and the metathorax; ou 

 the back part of the metathorax are two straight spines inclined back- 

 wards ; pedicle elongated ; scales small, nodose, and of nearly equal 

 size; abdomen triangular, smooth and shining, sub-acute; legs long; 

 coxae and trochanters large ; has cells in the decayed parts of trees, 

 and when disturbed often turns up its abdomen into a nearly vertical 

 position ; often seen going in ranks up and down trees. 



Female. Varies in color, in some the whole body is black, except- 

 ing the abdomen, which is banded with yellowish-white on the margins 

 of its segments; in others the head is of a pale yellow; head small, and 

 narrower than the prothorax, subtriangular, and rounded above and 

 behind ; thorax large ; prothorax raised above the head, the whole 

 thorax compressed laterally and narrowed backwards, with its divisions 

 strongly marked ; abdomen large, ovate ; wings not seen ; otherwise 

 like the worker. 



Common in Central Texas. 



67. Oecodoma (Atta) bicolor, n. sp. 



Length 0.12 inch. — Head, thorax and legs chestnut-red; abdomen 

 piceous or reddish brown, shaded more or less with black ; head sub- 

 triangular, rounded above, and emarginate behind; eyes small, circular, 

 and situated about midway of the head on the upper margins of its 

 sides ; flagellum of the antennae clavate and hairy, with its joints 

 short, excepting the apical ; mandibles small, triangular, curved in- 

 wards and acute ; prothorax narrower than the head, compressed and 

 rounded above ; mesothorax small and depressed ; two spines, short 

 and inclined backwards on the metathorax; scales of the pedicle 

 small, and irregularly nodose ; abdomen ovate ; abdomen and thorax 

 sprinkled with a few hairs. 



Dwells in the ground but a few inches beneath the surface in North- 

 ern Texas. 



