400 Bulletin American Mtiseum of Natural History. [Vol. XXI, 



parasitic origin. The nesting habits of difficilis resemble those of 

 F. integra on a small scale, especially as a colony is confined to a 

 single nest. See my paper: 'A New Type of Social Parasitism 

 Among Ants,' Bull. Am. Mus. Nat. Hist., Vol. XX, 1904, pp. 347-375. 



76. F. exsectoides Forel.- — Newfoundland (Davis); Palisades 

 (Beutenmueller) ; Alpine (Am. Mus. Coll.) ; Ramapo Mountains 

 near Halifax (Wheeler). 



This "mound-building ant of the Alleghanies," as McCook has 

 named it, is found nesting in open glades or clearings in the more 

 hilly portions of the State. The mounds which it constructs of earth 

 and vegetable debris are regularly dome-shaped and usually vary 

 from 3-4 ft. in diameter at the base and 1-2 ft. in height. They are 

 exposed to the sun, though often covered with living grass except 

 at the summit. The entrances are very numerous and mostly con- 

 fined to a broad girdle around the base. A single colony often 

 extends over several mounds. The workers, which are easily dis- 

 tinguished from those of all our other species of Formica by the 

 excised posterior border of the head, are very pugnacious. Like the 

 European F. exsecta they have a habit of sawing off the heads of 

 other ants. 



77. F. pallide-fulva Latreille. — Of this typical form of the species 

 I have seen a single worker from Cape May (Coll. Phila. Acad.). 

 This is probably very near the northernmbst range of the form. 



78. F. pallide-fulva schauf ussi Mayr. — Caldwell (Cresson) ; Cam- 

 den Co. (J. B. Smith); Da Costa (Fox and Daecke) ; Lucaston 

 (Daecke) ; Clementon (Viereck) ; Alpine (Am. Mus. Coll.) , Fort Lee, 

 Halifax, and Lakehurst (Wheeler). 



This is one of our commonest species of Formica. It forms 

 rather small colonies and nests under stones or in small obscure 

 mound-nests in sunny and grassy fields. In the barrens about Lake- 

 hurst, where there are no stones, it nests in the dry pine logs or in the 

 pure sand. It is timid and runs very rapidly. Its food seems to 

 consist very largely of the excrement of Aphides and the carcases of 

 insects. 



79. F. pallide-fulva schaufussi var. iacerta. Emery. — -Recorded by 

 Emery from New Jersey. This variety is common in the same 

 localities as the typical schaufussi from which it differs merely in 

 somewhat darker coloration and in having fewer hairs on the chin 

 and border of the petiole. 



80. F. pallide-fulva nitidiventris Emery. — Recorded by Emery 

 from New Jersey. The workers are smaller than those of the two 



