collected near Aden by Col. J. W. Yerbury. 415 
sinks the name ‘ Syrphus ericetorwm’ in favour of ‘ Sce@va 
eae 
salvix, still the question arises whether the matter was 
not out of his hands, and whether, having described the 
insect, he was not bound to abide by his first description. 
This is a common species throughout the Oriental 
Region.” 
The old description of S. ericetorwm is unrecognisable. 
6. Baccha sapphirina. 
“ Baccha sapphirina, Wied., Auss.-eur. Zweifl., ii, p. 96. 
Very common in the neighbourhood of Aden, this 
species occurs also in Ceylon (rare) and the Bombay 
Presidency (Deccan?) where it appears to be un- 
common.” 
7. Hristalis eneus, Scop., var. taphicus. 
“ Eristalis taphicus, Wied., Auss.-eur. Zweifl., ii, p. 191. 
Very common.” 
When examining various type collections of Diptera in 
-1896, I came to the conclusion that I could not consider 
EL. taphicus as anything but a tropical form of Z. xneus, 
and the specimens taken by Col. Yerbury strongly confirm 
me in that opinion; some of his males would pass for true 
LH. eneus, and I possess European and even British females 
which might be considered almost /. taphicus. 
8. Hristalis teniops. 
“ Hristalis teniops, Wied., Zool. Mag., xi, p. 42. 
ELristalis torridus, Walk., List Dipt. B.M., p. 612. 
Eristalis egyptius, Walk., List Dipt. B.M., p. 621. 
wD 
A single specimen Aden, 23.2.95. 
9. Hristalis quinquelineatus. 
“ Hristalis quinquelineatus, Fabr., Spec. Ins., ii, p. 425, 
21. 
? Eristalis punctifer, Walk., Ent., v, p. 274. 
2? Eristalis tabanoides, Jaennicke, Abh. Senckenb. Ges., 
vi, p. 402. 
Rather uncommon, found sitting on the wet mud 
