162 S. B. Buckley on North American Formicidse. 



nent, sublateral, and placed about midway of the head on the upper 

 surface; antennae inserted in front a little back of the base of the cly- 

 peus; mandibles slender, widened anteriorly, toothed on the inner 

 margins; ocelli prominent and on tup of the occiput; under surface 

 of the head somewhat flattened, not sinuate; prothorax one-fourth 

 wider than the head, rounded above, at the sides and in front, widest 

 in the middle ; mesothorax not depressed, about as wide as the protho- 

 rax and rounded at the sides ; metathorax a little depressed and a little 

 narrower than the mesothorax, subtruncate; scale incrassate, thick, 

 wedge-shaped ; abdomen truncate in front, oblong ovate, acute ; legs 

 slender ; upper surface of the head, back part of the thorax and abdo- 

 men thinly sprinkled with hairs ; whole surface smooth and shining ; 

 wings extend 0.12 inch beyond the abdomen, with one marginal and 

 two submarginal cells, no discoidal cell. 

 Ihib. — Fort Tejon, California, (Norton). 



17. Formica tenuissima, n. sp. 



Worker. Length 0.09 inch. — Reddish-yellow; legs pale yellow; 

 head triangular, rounded above and behind, and slightly so on the 

 sides ; eyes large, circular, lateral, and placed in front of the middle ; 

 antennae long, filiform and not clavate; mandibles small, slender, curv- 

 ed inwards and downwards, acute; under surface of head longitudinal- 

 ly sinuate; prothorax narrower than the head, round and smooth 

 above and in front, where it is widest, a slight depression between the 

 rneso- and metathorax ; metathorax nearly as high as the prothorax, 

 but narrower; pedicle short; scale large, erect, wedge.shapecl, and 

 slightly inclined forwards; abdomen ovate, obtuse; legs long, slender; 

 whole ant smooth, with a few scattering hairs on its upper surface. 



Hob. — Central Texas, in ground beneath stones. Rare. 



18. Formica perminuta, n. sp. 



Worker. Length 0.08 inch — Yellow or reddish-yellow; legs and 

 abdomen yellowish-brown ; head subtriangular, rounded above, occput 

 emarginate, the posterior angles slightly rounded ; eyes large, circular, 

 in front of the middle, and on top of the head near the lateral margins; 

 mandibles slender, somewhat projected in front, curved near the apex, 

 with five minute teeth ; club of the antennae equal in length to the fla- 

 gellura, which is short-jointed; prothorax narrower than the head, 

 smooth and rounded in front, above, aud largest about one-third dis- 

 tance back to the mesothorax, which is depressed or slightly strangu- 

 lated at its junction with the metathorax ; metathorax round and 

 smooth above, slopes gradually to the pedicle, which is short and in- 



