192 JOURNAL, NATURAL HIST. SOCIETY OF SIAM Vol. I. 
and on the thorax. This is an unusual type of illumination for 
the Lampyridae, but the genus Dioptoma is one of those of 
rather doubtful systematic position to which reference has been 
made above. Tothis genus may possibly belong the undetermin- 
ed Siamese female mentioned earlier, which, Mr. Gairdner informs 
me, behaved in a very similar manner. 
The Fireflies of Southern Europe have been critically observed 
by Emery (2) and others, and only this summer my friend Mr. Hugh 
Main and I spent several evenings at Lugano watching the behaviour 
of Luciola italica. In this species and its allies, both sexes are winged, 
but all the specimens caught on the wing are found to be males. The 
females closely resemble them, but are rather smaller and less parallel, 
with the eyes very much smaller in proportion. They are of a more 
sluggish disposition, and are found lurking in the grass and low her- 
bage. Very soon after sunset the lights of the flying males may be 
observed sparkling over the grass ; as it becomes darker a careful search 
will probably detect the fainter more continuous light of the female 
close to the ground. If one of these be kept under observation, the 
light will be found to disappear at intervals, then to shine again, some- 
times continuously, somatimes with a flushing periodicity much slower 
than that of the male. Waile the light is shining, a passing male perceiv- 
ing it will alter his course and fly down, alighting near the female; he 
then approaches flishing vigorously, as if not quite sure ef her exact 
whereabouts, until he finds her, when the lights of both are extingui- 
shed. Even when one male is in attendance the female may start 
flashing again to attract another, and it is not uncommon to find a 
small group of miles gathered round one female. Though often ob- 
served quite early in the evening we frequently noticed that the lights 
of the females were more numerous and brighter about 10 or 11 p.m. 
when the lights of the males were becoming scarcer, as though the 
females, despairing of attracting a mate, were becoming bolder in their 
efforts. In this species as observed by us, there was no suggestion of 
the synchronous flashing in concert of large numbers of males that is 
recorded of another European species as well as of numerous tropical 
species both of the Old and New Worlds, and which is mentioned by 
Mr, Gairdner as being very striking in the case of certain Siamese 
species. 
(2) Bull. Soe. Ent. Ital, 1886, p. 406. 
