Igt5.] E. BRUNETTI: Notes on Oriental Syrphidae. 213 
Macquart’s bengalensis may be anything; he separates it 
from taeniata, Mg., on the shorter abdomen, with wider (yellow) 
bands, the 4th segment being tawny with a dorsal line. Though 
no individual specimen answers to this amongst those before me 
it may very well be my ‘‘ Form 1.”’ 
Bigot’s description of his zmdiana (o@), from Bengal, though 
more lengthy is very inconclusive and may easily be the same 
form again. His ‘‘ derniers segments des tarses un peu brunatres”’ 
cannot be regarded as pointing to my wmigritarsis, in the three 
@ @ of which the tarsi are very distinctly wholly deep blackish or 
blackish brown. 
The characters studied in the present differentiation of forms 
are as follows :— 
(1) Length of 3rd antennal joint. This is always simply 
elongate or almost rounded, except in scwutellavis, F., a very 
distinct species which may be recognized at once by this character 
alone. 
(2) Markings on frons and face, or absence of same. 
(3) Thoracic dorsum with pale grey stripes or not. 
(4) Scutellum with yellow or black hairs, or both. The 
best way to decide this is to view this part from behind and 
slightly above. If wholly yellow haired, hardly any pubescence 
can be seen at all at this angle, whereas any dark hairs are 
visible at once. 
(5) Abdominal markings. 
(6) Comparative length of wing and abdomen. One or two 
of the older writers spoke of the wing being longer than or equal 
in length to, the abdomen. It is the abdomen, which in some 
species (scriptus, L., of Europe, for instance) is abnormally long, 
that varies, the proportional length of the wings to that of the 
rest of the body being the same in all the forms now treated of.! 
Moreover it appears to vary within reasonable limits, and if 
‘form 2’’ is the same species as my ‘‘ flavoabdominalis’’ form, 
the proportionate length of wing to abdomen will prove to be of 
less value still. 
(7) Coxae all yellow, or black marked. This hardly affects the 
Indian forms at all. 
(8) Hind tibiae mainly yellow or mainly black. This charac- 
ter only serves to separate the second well known and distinct 
species javana, W., which has them wholly black except for a 
clear cut median yellow band of some little width ; all the other 
forms possessing entirely yellow hind tibiae. It is true that 
scutellaris often has an indistinct obscure ring about the middle, 
but the very elongate 3rd antennal joint will always distinguish 
that species. 
1 If there is any exception td this it is in my ‘ flavoabdominalis’’ torm 
amongst the [Indian ones, and in scriptus, L., with its varieties, amongst the 
European ones. 
