HYMENOPTERA. 37 



123. FORMICA MACROCEPHALA. B.M. 



Formica macrocephala, Erichs. Wiegm. Archiv (1842), 229, 

 259 ?. 



Hab. Tasmania. 



SUBDIVISION 2. 



Anterior wings with one marginal and two submarginal cells ; 

 the discoidal cells obsolete. The ocelli usually obsolete in the 

 workers. (Sp. 124-138.) 



124. FORMICA? ERYTHROCEPHALA. B.M. 



Formica erythrocephala, Fabr. Ent. Syst. ii. 351. 6. 

 Atta erythrocephala, Fabr. Syst. Piez. 423. 5. 



Hab. New Holland. 



The typical specimen of the species is in the Banksian Collec- 

 tion ; it is a very slender, attenuated form of a worker ant ; the 

 head is a little wider than the prothorax, elongate, and of a blood- 

 red colour ; the antennae red, with the scape obscurely so ; the 

 mandibles porrect and finely denticulate on their inner edge. 

 Thorax elongate, narrowed towards the head ; the legs elongate, 

 slender, and with the knees and tarsi red. The abdomen small, 

 ovate, and subpetiolate ; the scale of the peduncle small, incras- 

 sate, rounded in front, and truncate behind. 



125. FORMICA INTREPIDA. B.M. 

 Formica intrepida, Kirby, Trans. Linn. Soc. xii. 4/7 



This species is probably the large form of the worker, the F. 

 basalis being the smaller form ; this can only be decided by an 

 examination of a community. F. intrepida has the head, the 

 basal joint of the antennas, and the abdomen black ; the thorax, 

 scale, and legs red ; the scale is ovate and entire above ; the ex- 

 treme base of the scape is red ; the inner margin of the mandi- 

 bles is slightly rufo-piceous, and armed with six teeth ; the length 

 of the insect from the tip of the mandibles to the apex of the 

 abdomen is 7 lines. 



Hab. Australia. 



126. FORMICA AGILIS. B.M. 



Worker. Length 5 lines. Head and abdomen black; an- 

 tennae, thorax and legs ferruginous. Head oblong, rounded 

 behind; eyes ovate and prominent, placed backwards on the 

 sides of the head ; the clypeus with a central longitudinal carina, 



