180 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, 1892. 



is some doubt wlietlier this is not a synon3^m of Tetr. lanuginomm 

 (E,oger ) , in wliicli case it will become TriglypJiothrix lanuginosus. I 

 cannot repeat too often tnat sucb points must necessai'ily be left 

 doubtful for the present. Dr. Forel can only devote bis studies to 

 one genus at a time. A monograph on Gamjionotus has been com- 

 pleted and another genus is in hand, the rest must wait their turn. 



Gen. 32. Holcomyrmex (Mayr). 

 The antennae are 12- jointed, the 3 terminal joints, forming the 

 club, are shorter than the rest of the flagellum [i.e., than the rest of 

 the antennae, excluding the scape, or first joint) : the abdomen is 

 truncate at the base. 



125. H. scahiceps (Mayr). . 



Poena Dists ..(10-3-90, ?). 



Kanara E. H. Aitken. 



C. Provinces J. A. Betham. 



Salem, Madras A, Burroughs Sharps. 



Thana Districts F. Gleadow. 



Nuddea; Barrackpore G. A. J. Rothney (type). 



Rai Bareilli, Oudh Dr. Simpson, 



Orissa Jas. Taylor. 



In a community of this genus there are ^ of all sizes. ILolcomyrmex 

 is, as a rule, a most industrious harvester, and sets about her 

 work in a most methodical way. The ^ never forage individually 

 for grain, but all take the same road and all return by the same 

 road ; the result being that every nest is the starting point of one 

 and often of several, well -beaten tracks, cleared of vegetation and 

 obstacles, and extending sometimes 100 feet and more in length. 

 How these tracks are engineered I have never discovered, but am 

 pretty certain that they are made gradually ; a commencement at 

 hazard is made, and, as the country immediately adjoining the road 

 is exploited, the road itself is carried forward. Whiere one of these 

 roads crosses a sheet of bare rock, it is there marked in white ; I can 

 only presume that this is the result of some chemical action, set up 

 by the formic acid exuding from the ants ; this acid, though too 

 small in quantity in a single ant to cause any appreciable effect, 

 might easily become sufficient when thousands of ants are continu- 

 ally passing, backwards and forwards, all day long. Holcomyrmex 



