Genus Pyretophorus. 15 
vannot understand. The wings have the spots on the wing field 
variable to some extent and also the costal spots, but the latter 
are most constant and peculiar and only occur in one other 
species (Marshallii). The only difference I see in the specimens 
described by Dénitz is that the first tarsal is spotted. I have 
only in one or two instances seen traces of pale scales. on the 
tarsi in costalis. Donitz appears to think the costalis figured 
by Giles in the “Memoirs” of the Liverpool School and those 
described by me are not Loew’s species. He does not exactly 
say what his idea of Loew’s costalis is, but appears to think my 
cinereus may be, yet at the same time he gives one point in 
which my costalis cannot be the real ccstalis: because it has 
faintly annulated legs. Why, then, should he say my cinereus 
comes near costalis and recommend it to investigators, when it 
also has banded legs? Mr. Austen identified costalis as Loew’s 
species, and I quite concurred in his identification. It is now the 
recognised costalis of Loew all over Africa where it occurs, 

Fig. 49. 
Wing of P. costalis(?). Loew (from Gambia.) 
except possibly in the Cameroons, and I think it is likely to. 
remain so until it is proved to be otherwise by an examination 
of the type, which I cannot trace. There is not the least doubt. 
Loew described a worn specimen in which the leg banding was 
indistinct ; in fact, I have seen fresh specimens in which it is 
nearly absent. As to Dénitz’s suggestion of renaming the species, 
I should not dream of doing it. The species has been so long 
known as costalis by all the important medical men in Africa 
that endless confusion would ensue, and without any just cause. 
The Gambian specimens bred by Dr. Dutton from larvae taken 
in a large pool at Bathurst showed great variation in regard to. 
the intensity of the costal spots and leg ornamentation. One very 
marked melanic form has been described here as a distinct variety. 
In 1902 Colonel Giles, I.M.S8., described a specimen given to 
me by Dr. Budgett from Gambia as a distinct species. I cannot 
