NOTES ON CORIZONEURA LONGIROSTRIS                 25

and internal anatomy, whilst their life-history is as yet entirely unknown. During
the past two years, the present writer has had occasion to make a search for the
early stages of C. longirostris, and although he has not been successful in his
attempts, he has nevertheless been enabled to record a few original observations,
which are likely to be useful to those interested in this group of flies.

         NOTES ON THE BIONOMICS OF C. LONGIROSTRIS.

         At Muktesar (Kumaun ; altitude 7,500 ft.), C. longirostris [P1. II, figs. 1(a) and
1(b)] has been observed to make its first appearance towards the latter part of July
and to disappear, in a remarkably sudden manner, towards the first week of Sep-
tember. This would appear to be, in the main, in accord with the experience of
Imms, who, as stated by Tetley [1917], found the flies † "on the basis of forests
towards the end of the rainy season, feeding on flowers of the orders Scrophularia-
ceæ and Labiatæ by thrusting their proboscis into them, poising themselves in the
air during the process". At Muktesar, C. longirostris has been noticed to feed upon
a species of flower, which the present vriter has had identified through the courtesy
of the Curator of the Herbarium of the Royal Botanic Garden (Sibpur), as Roscoea
purpurea, Smith (P1. II, fig. 2), belonging to the family of Scitamineæ. The seas-
onal prevalence of the flower almost synchronizes with that of the fly, both making
their first appearance and disappearing about the same time of the year. As al-
ready noted by L1. Lloyd (cited by Tetley, 1917), the long proboscis in these
flies is used to extract the nectar from flowers which they do while on their wings,
in the manner of Sphingid moths, and the present writer has found it relatively
simple to capture specimens of these flies while they are in the act of so doing.
The remarkable structure of the labellum would appear to be well adapted for
such operation in that it is a honeycombed paired process, provided with depress-
ions and tufts of backwardly directed spines (P1. III, figs. 3 and 4). The precise
function of the labellum has been discussed by Tetley (1917), who observes :
" Having inserted its proboscis into the flower, the insect would naturally make the
two labelia diverge so as to suck up the nectar ; this would have the effect of mak-
ing the spines project into the sides of the flower and would give the insect a slightly
firmer hold while it was hovering." The spatula-like double labellum, however,
presumably mainly functions in scooping out the nectar, the depressions and brush-
like tufts of spines aiding in the process.

         The question as to whether flies of this class are capable of sucking mammalian
blood has been discussed by several workers, and the different views have already

         †It is of interest that Dr. Imms's specimens were taken by him, on the 7th July 1922, at
Bhowali (altitude, 5,000 ft.), which is situated at a distance of about 16 miles from Muktesar.