160 S. B. Buckley on North American Formicidse. 



there is a slight strangulation; metathorax raised, widened, descends 

 gradually to the pedicle, which is inserted in the front base of the ab- 

 domen ; scale large, vertical, wedge-shaped ; abdomen truncate in 

 front, broad ovate, obtuse, thinly sprinkled with hairs; legs very long, 

 slender ; whole ant smooth and shining. 



Hob. — On trees in the Capitol Park at Washington, D. C. Not 

 common. 



12. Formica arenicola, n. sp. 



Worker. Length 0.13 inch. — Upper surface of head, thorax and 

 abdomen black or piceous, spotted with pale yellow beneath ; legs, an- 

 tennae and mandibles pale yellow ; head ovate, round above ; occiput 

 not emarginate ; antennae inserted at the base of the clypeus, long, cla- 

 vate; eyes large, black, elliptical, in the upper surface of the sides of 

 the head, about midway ; mandibles triangular, acute and finely tooth- 

 ed on their inner margins; under surface of the head not sinuate; pro- 

 thorax about one-half the width of the head, round above and at sides, 

 widest in front; mesothorax compressed and not depressed; metatho- 

 rax narrowed behind and inclined gradually to the pedicle; divisions 

 of the thorax not strongly marked ; pedicle short and inserted in the 

 base of the abdomen a little in front of the middle ; scale large, wedge- 

 shaped, inclined forward to the metathorax ; abdomen subtriangular, 

 with a broad base in front; whole ant smooth and shining, not 

 hairy. 



Hah. — Found in sandy soil near Washington, D. C. Has cells but 

 a few inches deep. 



13. Formica politurata, n. sp. 



Worker. Length 0.16 inch — Mouth, antennae, thorax, legs, pedicle 

 and scale, yellowish-brown, with piceous spots; the rest black; the 

 whole surface smooth and shining, with a few short hairs on the abdo- 

 men and upper surface of the head ; head ovate, rounded above, at 

 sides and at posterior angles ; eyes circular on the upper surface, sub- 

 lateral, large, and placed about midway of the head ; antennas inserted 

 at the base of the clypeus, slightly clavate ; mandibles small, short, 

 curved in, toothed and acute ; prothorax one-fourth narrower than the 

 head, rounded at its sides and somewhat flattened above, widest in the 

 middle; mesothorax not depressed, slightly compressed, higher and 

 narrower than the prothorax ; metathorax still narrower, sloping gra- 

 dually to the pedicle; scale vertical, thin, wedge-shaped; abdomen 

 ovate, obtuse. 



Ilab. — Michigan, (Norton). 



