S. B. Buckley on North American Fonnicidse. 165 



22. Formica insana. n. sp. ("Crazy Ant.") 



Worker. Length 0.1-1 inch — Color black or brownish-black, smooth 

 and shining throughout; head sub-quadrate, the lateral margins slight- 

 ly curved inwards; below oval, and rounded above; eyes large, sub- 

 ellipticai, and placed on the anterior portion of the head near its lateral 

 margins; antennae long, filiform ; mandibles large, curved inwards, the 

 truncated apical ends sharply toothed; head sub-channelled beneath, 

 with the anterior and posterior parts deeply depressed ; prothorax 

 about half the width of the head, rounded above; mesothorax some- 

 what depressed : metathorax has a rudimentary spine or sharp protu- 

 berance on its upper posterior surface, pedicle short, inserted near the 

 base of the anterior part of the abdomen ; scale small, wedge-shaped, 

 and inclined forwards; abdomen broad-ovate, subacute; legs small, 

 slender, and rather short. 



Female. Length 0.20 inch. — Head small, narrower than the tho- 

 rax ; abdomen broad, oblong and ovate ; color black-bronze, with the 

 margins of the segments of the abdomen hyaline ; thorax raised above 

 the head ; wings not seen ; the remainder like the worker. 



Dwells in the ground but a few inches deep, having numerous 

 holes scattered over a large surface of fifty or more feet in diame- 

 ter. It goes now here and now there, without order, from one abode 

 to another, sometimes moving the larvae from one place to another ; 

 large colonies dwelling in common. It is very active and war-like, can 

 conquer most other ants, boldly seizing the larger species by the legs. 

 If a large ant is so unfortunate as to run among the "crazy ants,'' he 

 hastens to escape, but rarely does so without being severely bitten. 



Common in Central Texas. 



23. Formica masonia, n. sp. 



Worker. Length 0.11 inch. — Color brownish-black, paler beneath ; 

 head cordate, with its upper surface subrotuud ; ocelli absent; eyes 

 large, prominent and lateral, placed in the anterior portion of the head; 

 occiput emarginate, with its posterior angles rounded; antennae long, 

 filiform ; mandibles small and of nearly uniform width, curved inwards, 

 with two teeth at the apex ; under surface of head round, with a slight, 

 depression at the men turn and the occiput ; prothorax about one-third 

 narrower than the head, compressed and narrowed posteriorly, rounded 

 and smooth above ; mesothorax slightly depressed ; pedicle short and 

 inserted in the anterior portion of the base of the abdomen ; scale small, 

 subnodose ; legs long, slender; whole ant smooth and glossy. 



Female unknown. /^""r*^ 



