S. B. Buckley on North American Formicidx. 159 



9. Formica parva, n. sp. 



Worker. Length 0.10 inch. — Black; legspiceous; smooth through- 

 out and of slender form; head ovate, rounded above, at the sides and 

 behind, not cmarginate; eyes large, elliptical, in front of the middle 

 near the sides ; antennae long, subclavate, inserted at the base of 

 the clypeus; mandibles small, curved in, acute; head broad, sinuate 

 below; prothorax narrower than the head, somewhat flattened above, 

 rounded at the sides, widest in the middle; mesothorax somewhat de- 

 pressed, narrowed behind ; metathorax compressed ; scale small, no- 

 dose ; pedicle short, and inserted in the anterior part of the base of 

 the abdomen ; abdomen broad, ovate, acute. 



Hab. — Near "Washington, D. C, beneath stones. 



10. Formica atra, n. sp. 



Worker. Length 0.19 inch. — Black ; trochanters, tibiae and tarsi 

 subhyaline ; head subovate, rounded above, at the sides, and at the pos- 

 terior angles ; occiput not emarginate, front of the head of about the 

 same width as the back ; antennae inserted at the base of the clypeus, 

 long, filiform, and not clavate; eyes small, circular, lateral, and a little 

 back from the middle of the head; mandibles small, curved inwards, 

 and toothed on their inner margins ; head not sinuate below ; protho- 

 rax but little narrower than the head, rouuded above, in front and at 

 the sides, widest a little in front of its middle ; meso- and metathorax 

 compressed and narrowed back in the same plane; metathorax sub- 

 truncate ; scale narrow transversely, wedge-shaped ; pedicle inserted 

 in the anterior part of the base of the abdomen ; abdomen obovate, the 

 first segment round, narrow in front, widened behind; legs long, slen- 

 der; whole ant of slender, elongated form, smooth and shining; the 

 upper margins of the segments of the abdomen thinly sprinkled with 

 hairs. 



Hab. — On trees in the environs of Washington, D. C. 



11. Formica Virginiana, n. sp. 



Worker. Length 0.20 inch. — lleddish-yellow ; head ovate, round- 

 ed above, at the sides and behind; eyes large, black, circular, lateral, 

 near the top about midway of the head ; antennas inserted at base of 

 the clypeus, long, clavate ; mandibles large, subtriangular, curved in 

 at the apex, 5-toothed, apical tooth long, acute; clypeus somewhat de- 

 pressed, round, smooth, under surface of the head not channelled ; 

 prothorax narrower than the head, rounded above, in front, at the 

 sides, widest in the middle ; mesothorax narrower than the pro- or me- 

 tathorax, compressed, and depressed back to the metathorax, where 



