1136 lllE BUTTERFLIES OF NEW ENGLAND. 



tergradation of foniis, due probably to the intermingling of those which 

 have been born at higher and lower levels. 



Enemies. Strange to say, not a single parasite has been reported to 

 attack this connnon insect ; but Cockerell says a large Asilid Hy preys 

 upon the butterfly in Colorado. 



Desiderata. The principal point which awaits complete solution is the 

 exact relationship of the form eriphyle to this species. That it belongs 

 here is absolutely certain from the breeding experiments of JMr. Edwards, 

 who has solved so many other points in the historj' of our butterflies. But 

 now tliat it is known to be a form of this species, its direct seasonal 

 relation to the other forms needs careful investigation both in the north and 

 especially in those southern regions where the two yellow forms, eriphyle 

 and ariadne, come into close conjunction or overlap. This of course can 

 be undertaken only by those on the spot or at least tlu'ough their aid, and 

 it is recommended that collectors in such districts should forward to Mr. 

 Edwards eggs and young larvae of known parentage with abundance of 

 the food plant. The observations also upon the other forms need to be 

 multiplied in many localities, not the least upon the Pacific coast, in order 

 to clear up the complete history of the species, and to no one better than 

 to Mr. Edwards can be entrusted the working out of these problems in 

 their relation to each other. Careful comparison should also be made 

 between the seasons of this species and those of its allies wherever it is 

 associated with others, as it is indeed with one species or another in nearly 

 every part of its range. Such comparisons are desirable in part to answer 

 questions that may arise concerning the hybridization of this butterfly with 

 its relations. We know too little of the seasons of this species in the most 

 northern parts of its range, where it would seem probable that it must be 

 only digoneutic, so that it is specially desirable that those residing in the 

 Dominion of Canada should follow up the history of this butterfly in their 

 own district in many places. This has partially been done in Nepigon by 

 Mr. Fletcher, l)ut needs to be carried out still more fully. The parasites 

 of this butterflj' need to be investigated, or if it really enjoys immunity 

 from them, the cause of such immxmity should be sought. 



LWr OF ILLUSTRATIONS.— EURYMUS EURYTHEME. 



Generril. Chrysalis. 



PI. 25, Hij. 8. Distribution in N. Aiupikn. Pi.84, fig. 53. Side view. 

 Egg. Imago. 



PI. 65, fij. 22. Colored. PI. IS, tig. 4. Male, both surfaces. 



C<ilerpillur. 7. Female, upper surface. 



Pi. 76, fig. 1. Full grown caterpillar. .35:6. Male abdominal appendages. 



70:61. Head, fifth stage. 



