122 THE ENTOMOLOGIST. 



The Papilionidae and Nymphalidae are in reality quite out of 

 focus with each other. The speciahzation of the former is 

 cubital, of the latter radial. The incongruity between the two 

 should be felt by the naturalist. The correspondences are due, 

 in my opinion, to convergence. 



My general defence for my classification of the diurnals lies 

 in the fact that we cannot interpolate the Papilionides at any 

 point without breaking a continuous succession of forms having 

 certain leading characters in common. My general defence for a 

 diphyletism of the diurnals, not previously urged by any author, 

 lies in the fact that the direction taken by the specialization of 

 the anal veins in the Papilionides is unique. The families of the 

 Hesperiades appear to converge in an ancestral type to the ex- 

 clusion of the Papilionides. The convergence of the butterflies 

 is already assumed by Dr. Chapman. 



In the following table of characters, by which I separate the 

 diurnals into two series, I do not undertake to settle the homology 

 of the retained anal veins, and Dr. Chapman will, I hope, help 

 us here. As I have pointed out, there is a law of inequality in 

 specialization, in one and the same organ, here the veining of 

 the wings. The development of one system of veins does not keep 

 pace with another, nor is the ratio of advance the same as between 

 the front and hind pair of wings. 



In the Pseudopontiadae three anal veins are retained on the 

 hind wings, otherwise the specializations conform to those of the 

 Hesperiades. Under the term Nymphalidae I include the " brush- 

 footed " butterflies, the Nymphalidse proper, the Agapetidse (Sa- 

 tyridse), Morphidae, Heliconidae, and Limnadidae (Danaidae). 



IMAGINAL WING. 

 A. Papilionides. B. Hesperiades. 



Fore wings with. ^' Grote's vein" Fore luings with second anal 



and second anal persistent ; traces only persistent, with a fork at base 



of first anal (submedian fold) as a vanishing through reduction ; traces 



scar seldom wanting. of first anal as a scar oftenest wanting. 



Hind wings with one anal vein Hind wings with at least two 



alone remaining. anal veins persisting. 



Specialization of Media. Specialization of Media. 



/'Pierididae 



Cubital 



Eadial NymphaUdae 



j Parnassiidffi 



(TeinopalpidjE ^^^^^^ 1 Libytheids 



lEiodinidae 



Central PapiHonid» Cubital [^ttX^tZ 



Central (Lycajnidie 



( Hespenadse 



It is hoped that the designations proposed by Prof. Comstock 

 for the subcostal vein, the radius, cubitus, and anal veins will be 

 permanently adopted. 



