194 JOURNAL, NATURAL HIST. SOCIETY OF SIAM Vol. 1. 
No male was observed to reply to the flash of a creeping 
male. 
P. consanguineus, The male gives a double flash in quick 
succession followed by a pause, then another flash, and so on; the 
female replies within a second to the second flash of the male. A 
particular female would not reply to the flash of a match, but would 
answer the double flash of a bulb when 20 or 30 feet away; ona 
nearer approach she seemed to recognise something unusual and would 
not reply. 
P. scintillans. The male gives a short single flash, and the female 
a longer single flash. 
A female would reply tothe first flash of a male of P. cou- 
sanguineus but the latter takes no notice. The female of this species 
is apterous. 
P. marginellus. The male gives a single short sharp flash yellower 
than that of P. scintillans: the female replies with a double flash, the 
first sharper and brighter than the second and followed at once by the 
second. The reply is given very quickly after the flash of the male. 
P. castus. The male gives a single flash not so short and sudden 
as that of P. marginellus; the female gives a single flash very much 
like that of P. scintillans but delivered immediately after the flash of 
the male ; there is no distinct pause asin P. pyralis and no indication 
of doubling as in P. marginellus. These last two species are very 
similar, and indeed by some authorities they have been considered to be 
merely forms of the same, Mr McDermott admits that he can find no 
structural difference between them, bat their flash is so distinct thas 
he considers them good species. They are frequently found flying to- 
gether but no case of interbreeding has bsen observed though specially 
watched for. 
Careful observations of this nature, not only upon Tireflies but 
upon insects of any sort are very badly wanted. ‘T'oo often such habits 
are regarded as merely everyday events of no particular interest, yet out- 
side the particular region in which the species occur very little is known 
about them. At the same time it is very necessary that the species of 
which such habits are recorded should be correctly determined; notes on 
the habits of any animal only vaguely or loosely specified are of little 
use, hence it is essential, if any observations are to be of scientific value, 
that specimens should be collected and their identity definitely establi- 
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