508 Dr. 'T. A. Chapman on the 
It may be Me enient before treating the species in 
order, to consider first those as to which I have anything 
definite to say as to specific separation or otherwise of 
forms, as a result of studying the appendages. 
In 1867 Knaggs introduced ingratella as a British 
species (EK. M. M., iv, p. 61, 1867), but this was afterwards 
abandoned on the ground that Knaggs’s specimens were 
only varieties of dubitalis. 
When we examine the appendages we find those of 
dubitalis and ingratelia quite identical, except as to size, 
dubitalis being the smaller. The cornuti are placed in a 
row, are five or six in number, the most forward (whilst 
still within aedoeagus) the larger, the rest dwindling 
regularly. When we get a side view of them this is very 
obvious, but if they happen to be superposed, it is at first 
difficult to see that they are not one long rod, until the 
several bases are discerned, the tips being in this position 
quite obscured. 
If there is no difference here what is the difference 
otherwise? It is an almost inappreciable one of size. 
Dubitalis has an expanse of 18 mm. up to 22 mm.; 
ingratella 20 mm. to 23mm. My specimens of the latter 
are some sent by Zeller to Barrett, some received from 
Staudinger are identical, so that I believe I have the true 
ingratella. Dubitalis var. ingratella from Mr. Bankes is 
very like those I have as ingratella. The chief differences 
I can see consist in the claviform stigma being more 
usually open in dubitalis, closed, 7. e. without a distinct 
pale centre, in ingratella. 
Dubitalis has a paler whiter colour, and the markings 
are more distinct; ingratella is of a warmer yellower tint, 
and the markings are pale ; it exaggerates, but marks the 
difference, to say that duditalis has some of the markings 
black, in ingratella they are merely an accentuation of 
the ground colour. But specimens that are taken with 
dubitalis, and are, I presume, undoubtedly dubitalis, in- 
cluding English ingratella, vary in the same directions 
and are in fact indistinguishable from ingratella. I con- 
clude that ingratella is a larger, paler as regards mark- 
ings, richer as regards ground colour, form of dubitalis, 
a southern form, if not absolutely geographically, at least 
as regards summer temperature. 
Ambigualis and atomalis might be dealt with as being 
closely parallel to dubitalis and ingratella. They need 
