18()2.] 



•Ill 



Formica latipes n. sp. 



Wo have another yellow ant, the 9 of which is scarcely distinguishable 

 from 9 f"- aphidivola but by its being a trifle smaller and paler. The % 

 is exactly alike, but the 9 differs most remarkably, 1st in being ferruginous, 

 with the thorax more or less piceous; 2nd in having short, robust anten- 

 nae, no longer than those of 9 . which has a body only half as long; 3rd 

 in having femora and tibiae so strongly and widely compressed as to be not 

 much more than twice as long as wide, and truncate at tip, the femora 

 deeply excavated at tip to receive the tibise; 4th in the whole body be- 

 ing covered with a long cinereous pubescence. This species is, so far as I 

 am aware, undescribed. 



Length % .15 — .17 inch; 9 .35 — .36 inch; 9 .13 — .15 inch. Expanse S 

 .39-.43 inch; 9 .80-88 inch. Described from 14 S , 2 9 , 5 9 from the same 

 nest. Of the 14 S , 8 had a recurrent nerve in both wings, 3 in one 

 wing only, and 3 in neither wing, the nerve when present often abbrevi- 

 ated as in the preceding species. In both 9 the recurrent nerve was 

 present and unabbreviated. I have noticed a similar variation in another 

 species of Formica, which shews that Say's subdivision of the genus is not 

 natural nor practically reliable. 



RECAPITULATIOxV OF U. S. APHID.E. 



Eock Island, Illinois; Nov. 5, 1862. 



