stridulation wn ants. 207 
margin of the second node, by which these lines are 
scraped is excessively thin. 
Myrnicipes. — Aphenogaster barbara (worker). EK. 
Pyrenees. The neck formed by the base of the segment 
behind the second node is short, but it is prolonged 
forwards somewhat in the middle of the dorsal region, 
so as to be longer there. The whole of the median part 
is covered by excessively fine lines, very densely packed, 
uninterrupted, and quite straight. The surface at the 
sides of the neck has a very minute, dense, quite diffe- 
rent sculpture. 
Female.—Malta. The surface covered by the fine 
lines is very much less, and the lines are many of them 
largely interrupted, as might happen when a diamond 
making a very fine scratch on glass missed its hold of 
he glass now and again. 
Myruicipes. — Sima, sp. Fremantle, W. Australia. 
The neck of the segment is rather long, and there is a 
stridulating band on the middle; the striz on the front 
part are coarser than the neighbouring sculpture, and 
on the apical part are much finer; there is an abrupt 
line of demarcation between the coarse and fine lines. 
This species is unique amongst those I have examined 
in having the stridulating band divided into two parts, 
one consisting of coarse, the other of fine, lines; a 
stridulating performance by this insect might produce 
very extraordinary effects. The fact that the basal lines 
are coarser than the neighbouring sculpture is without 
any parallel in the other ants I have examined, and 
appears to indicate that the division of the stridulating 
band into two parts is of importance. Possibly a 
sound from this insect might begin as a sort of roar, 
and in the middle of its utterance suddenly change to a 
sort of squeak; on the other hand, by using at one time 
the anterior part, at another the posterior part of the 
file, two different and even abruptly contrasted sets of 
sounds might be produced. Fig. 5. 
Sima rufo-nigra (worker).—East India. The sculpture 
of the neck of the first segment behind the second node 
is rather coarse, and in the middle of the dorsal region 
it becomes striz; these are not, however, very regular, 
and on the front part of the neck are coarse, while on 
the apical part they become finer and more regular ; 
this is in opposition to the neighbouring sculpture, which 
