202 THE CANADIAN ENTOMOLOGIST. 



belong, and which embraces also Basilarchia. Mr. W. F. Kirby writes 

 me that he cannot find that any new nan:ie has been proposed for 

 Megahira, Blanchard, 1840, preoccupied by Horsfield, 1820, and 

 Agassiz, 1833. (See Scudder, Historical Sketch, 212.) I have accordingly 

 proposed the above generic title for the type coresia. What is relatively 

 unimportant at the present time seems to be a discussion of rules limiting 

 the application of the law of priority, all of which are arbitrary in their 

 nature and cannot compel universal consent. What appears to me of 

 greater practical value is the fixing of the types of existing generic titles, 

 so that the use of these by themselves, without mention of any species, 

 may be intelligible. The discord is already such that much of what has 

 been recently written by the systematists on the Diurnals cannot be 

 followed or clearly understood. 



Issoria lathonia. — This is a distinct genus from Argynnis agiaice, 

 in which type vein III, is appressed upon the Radius to a point beyond 

 the cell, while really arising at a point within the cell. In Issoria 

 this appression, which prepares us for the point of emission of 

 vein III, in Melitc^a, has not taken place. In Issoria, vein III, is 

 brought nearer than in BreiitJiis hecate. These two types, Issoria and 

 Brenthis, appear more generalized than Argynnis. Both in Dryas 

 paphia and in Acidalia nipJie the appression has taken place as in 

 Argynnis, and I am at a loss to distinguish the genera from the neuration. 

 In the more specialized Agraulis all the branches arise beyond the cell. 

 With the lengthening of the wing the radial veins tend to arise beyond 

 the cell and reproduce the character found in Leptidia and other " long- 

 wings." In Diane iuno, vein III, has not progressed so far beyond the 

 cell as in Agraulis vani/ice. In Euptoieta claudia, vein III, has not 

 reached the extremity of the cell ; the cross vein is nearly vanished on 

 hind wings between IV. and cubitus, a specialization in the direction of 

 Melitcea. In Enphydryas phaeton the only deviation from the Melitcea 

 type is the very slightly more strongly retained cross vein on primaries. 

 This is hardly noticeable, and I am at a loss to distinguish the genus by 

 the neuration from Melitcea matnrna. I can also not distinguish 

 Cinclidia. The genera Acidalia, Dryas, Eup/iydryas and Cinclidia do 

 not afford neurational characters by which they may be distinguished, the 

 two first from Argynnis, the two latter from Melitcea. In Phyciodes 

 t/iaros, vein III, springs from Radius before extremity of cell ; vein 

 III as in Melitcea; vein III^ decidedly to apex <jf wing, as frequently 



