sept. 1896] Skinner: Study of N. American Butterflies. 115 
genus twenty species. Of these we have harfordii , moina , alexandra , 
edwardsii, emilia, of doubtful value. Now, in regard to hecla , meadii 
and we know them from Greenland and Iceland, Laggan and 
Colorado, but do we know that they are not found over the intervening 
territory, and do we know that if they are thus found they would not 
show intergrades or evidences of the effect of vertical distribution ? The 
Lapland hecla is quite different from the Greenland one, and shows as 
much difference as some of our so-called species. Danais strigosa is 
likely to prove a variety of berenice. 
In the genus Argynnis we have fifty-eight species, of which about 
eighteen are of doubtful value. I have a large amount of specimens 
with proper data and the more I get the less I know in one direction 
(in relation to species as listed) and the more in regard to the real 
value of variation. The wonderful and interminable variation in this 
genus has already been pointed out. The presence or absence of silver 
spots below is in many species of no value whatever, and my studies 
would lead me to believe that an unsilvered form always has a silvered 
form, of regular or irregular appearance, except in a few such species 
as alberta , astarte. We may also have hybrids each year which oc¬ 
cur annually, yet, of course, do not actually reproduce their kind. The 
difference produced by vertical and horizontal distribution is tremen¬ 
dous. Take, for instance, cybele from Maine and Florida, the difference 
is fifty-fold greater than between aphrodite from Maine and aphrodite 
from Colorado ( cipris ). Aphrodite from Maine and from the mountains 
of North Carolina are also wonderfully different in size and maculation 
arid really differ to a greater extent than some of the gradational forms 
listed as species. I am studying this interesting genus and will now 
point out so-called species which show gradational forms or have been 
proven one and the same thing. I have found white females of cybele 
like unto leto and would refer reader to Ent. News, Vol. V, p. 318. 
We want to know more about nitocris , but can’t do anything until 
we get more material. Cipris is the form of aphrodite found in Colo¬ 
rado. Alcestis I have, showing every intergrade into aphrodite. 
Electa is so close to atlantis as to hardly warrant a varietal name and 
differs no more than other local forms of atlantis. The one found at 
Nepigon is not exactly like either. The forms clustering around ition- 
ticola and rhodope are legion, hardly any two being alike. Chitone 
has hardly any two individuals alike and there are all grades of silver 
spots beneath—from nothing to a silver mine. Inornata is probably 
an unsilvered form of some of the other known species. Artonis (un¬ 
silvered) has been taken in coitu with {eurynome) silvered, both ways, 
