Sept. 1896 ] Skinner: Study of N.American Butterflies. 115 



genus twent}' species. Of these we have harfordii, moina, a/exatidra, 

 edwardsii, emilia^oi doubtful value. Now, in regard to hecla, meadii 

 and elis, 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 

 Avould 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 

 and 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 mon- 

 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 {eiirynome) silvered, both ways, 



