496 Records of the Indian Museum. (VoL. XI, 
My suggestion (Mem. Ind. Mus., III, p. 215) that Pleurarius 
brachyphyllus is probably not a gregarious species has proved to 
be incorrect. This species is abundant in the evergreen jungles of 
the lower western slopes of the Western Ghats in Cochin. Occa- 
sionally isolated pairs were found in a log, but usually numbers 
were found together. It is scarcely possible that insects of this 
species are able to fly; for although the wings are well developed 
the elytra are fused. How this fusion takes place I was unable to 
determine, as only one pupa was found, and no stages inter- 
mediate between this and the almost fully blackened adult. The 
elytra are not fused in the pupa. 
The conclusion that Episphenus indicus is to some extent gre- 
garious, and that EF. neelgherriensis is not, was confirmed by iny 
observations in Cochin. All of the three last mentioned species 
burrow more deeply into logs than does Leptaulax bicolor which, 
together with its larvae and pupae, was only found close under the 
bark. Pleurarius brachyphyllus, especially, makes galleries well 
below the surface, a fact which probably accounts for its compara- 
tive rarity in the collections I had previously seen. It often bur- 
rows in somewhat hard wood and is very difficult to dig out; but 
I found it even commoner in Cochin than Episphenus indicus, a 
species which was distinctly commoner than E. neelgherriensts. 
The larvae of Pleurartus brachyphyllus and Episphenus indicus 
—I got very few of Episphenus neelgherriensis and Leptaulax bicolor 
—were commonly found widely separated from adults. In some 
cases no adults at all could be found, and it is curious, in view of 
Ohaus’s observations on American species, that although all the 
larvae which I attempted to keep thrived for a time, whether 
associated with adults or not, only those without adults survived 
the journey to Calcutta; and that of these one or two lived for 
between one and two months. I regret now that I did not make 
an effort to keep single families by themselves. This was, how- 
ever, rendered almost impossible, firstly by the difficulty of recog- 
nizing a single family as it occurred scattered along one or more of 
the groups of burrows made by the various members of the 
colony, and secondly by an insufficient supply of separate tins. 
Stridulation in adults of both Episphenus and Pleurarius is 
brought about by movements of the abdomen, and is faintly 
audible at a yard or two’s distance from the ear. In larvae it is 
much fainter. I never saw any indication of its being used as a 
means of communication, and this agrees with Mr. Kemp’s 
experience of species found in the Abor Country. Adults, at least, 
appear to stridulate whenever they are disturbed, presumably in 
order to drive off the enemy. 
The stridulating organs resemble those of Popilius (Passalus, 
auct.) cornutus and Pentalobus barbatus! described by Babb (Exé. 
1 The abdominal part resembles that of Proculas goryi also; but the wings 
are not reduced as in that species. [I cannot understand Schulze’s statement that 
in P. goryt the abdominal part is situated on the fifth seg nent, for his figure (in 
which the first segment is omitted) clearly shows it on the sixth, where it is 
