NOTES ON THE VARIATION OF PERONEA CRISTANA, FAB. 13 
Curtis describes lichenana as having a dark button, whereas 
subvittana has a cream-coloured, or, as Stephens says, a whitish 
one. 
Ab. ruficostana, Curtis. Webb (loc. cit., vol. xliii, p. 868) eriti- 
cises Clark for creating a new name for the white vitta form of this 
group thus: “Curtis says of the type of rujicostana, ‘inner 
margin white,’ but Clark, that the true ruficostana is yellow.’ 
Which is correct ? If Curtis stands, alboruficostana, Clark, must 
fall, but for many years that with the white vitta has been in 
our cabinets as the typical form; the description must stand 
before any plate.” 
This is one of the least logical statements in the whole paper 
and should be wiped out from memory. Curtis, in ‘ British 
Entomology,’ first edition (1824), plate 16, figures the yellow 
vitta form as ruficostana. There can be no doubt about this: the 
figure is a very beautiful one, and the vitta is lemon-yellow. In 
his description, however, No. 24, he says: ‘‘ Inner margin 
(= vitta) white.” It is to be presumed that he figured a yellow 
vitta example, and described one with a white vitta, overlooking 
the discrepancy. ‘There may be something of weight in suggest- 
ing that when the average author describes a feature as white it 
should stand before his figure which makes it yellow, but in the 
case of Curtis it is different. The average author in writing on 
Lepidoptera gets an artist to produce his plates, whereas he writes 
his own descriptions, and thus an error is more likely to occur 
in the former than in the latter. But Curtis was his own artist, 
and whilst his figures are the finest that have ever been produced 
in any entomological book: in Britain, so exquisitely executed 
that there can be very little doubt as to the particular species 
he intended to represent in any one of them, the same excel- 
lence does not apply to his descriptions, which are in many cases 
only outlined. Unquestionably a figure that proceeded from him 
should stand before any of his descriptions when the two diverge. 
There is the additional objection to Webb's suggestion, that ‘its 
adoption would leave the form with a yellow vitta without a name, 
and a new one wouid have to be found for it. His remark that 
the form with the white vitta is the one that has been in our 
cabinets for many years as the type is no doubt correct, but that 
is not a reason why the error should be perpetuated. 
Ab. ruficostana, Curtis (with the yellow vitta), is by far the 
rarest form of the two. Out of several thousand examples of 
cristana forms examined in the five years I have studied the species, 
I have only come across one specimen, which came from the New 
Forest, whereas of the forms with the white vitta I have picked 
out about thirty. Mr. South has two examples of ruficostana 
from the New Forest. 
The descriptions of Desvignes constitute one of the chief 
difficulties experienced by students of the variation of cristana ; 
