184 ENTOMOLOGICAL NEWS [June, '22 



m astyana.v of the red spots on the upperside of the hindwing. 

 Therefore I would have referred the first specimen described 

 above to R. arthcmis f. proscrpina Edw., if it were not -for the 

 fact that the specimen was found in company with numerous 

 examples of astyana.v and not of arthcmis. Besides, as far as 

 I am aware, arthemis has not been found to occur in the vicin- 

 ity of New York City. 



The occurrence of a proscrpina-like form within a popula- 

 tion of astyana.v, which is not mixed with arthcmis, is rather 

 interesting. This fact, coupled with the well-known variability 

 of arthcmis itself and the geographical distribution of the two 

 butterflies, seems to suggest that they represent two local races 

 ( sub-species) of a single species : B. arthemis arthcmis, the 

 northern, and B. arthemis astyanax, the southern race. 



Another point that might be brought up in connection with 

 the variability of the reddish markings in astyana.v is the ques- 

 tion of mimicry in the genus Basilarchia. The well-known 

 resemblance of B. ar chip pus to Danais (Anosia) plc.vippus, 

 long believed to be a case of mimicry, has come in recent years 

 to be looked upon with much skepticism. There has been no 

 positive ground for the hypothesis of mimicry to begin with, 

 and in the case of archippus especially it has been shown that 

 in the ancestral form, B. arthcmis, which archippus is sup- 

 posed to have sprung from, the reddish markings show no 

 such wide variability as called for by the hypothesis of gradual 

 change by natural selection. That astyana.v shows much varia- 

 tion in its reddish markings would seem to open a path for the 

 hypothesis, which, however, does not seem to meet the condi- 

 tion. For the past three years, in the vicinity of New York 

 City, archipp-us has been observed more commonly than plcx- 

 ippus. The time of appearance, too, seems to be different in 

 the two species, they being seldom seen flying at the same time. 

 MoreO'ver, of the two Basilarchias occurring in this region, 

 the "unprotected" astyana.v is by far commoner than the sup- 

 posedly protected archippus, A question arises : Does archip- 

 pus derive any benefit from its resemblance to plc.vippus? 

 With these facts at hand, it might be well to consider if ar- 

 chippus is so different in the markings from other congeneric 

 forms as to require some special explanation. Is not Vanessa 

 antiopa, for instance, different enough from other Vanessas 

 to demand a special hypothesis to account for its unique color- 

 ation ? 



It is not within the scope of this short note to go into this 

 question any deeper. Suffice it to say that, while astyana.v 

 shows wide range of variability in the reddish element of its 

 wing markings, this fact by itself offers no argument for the 

 supposed mimetic nature of the coloration of archippus. 



