Dr. Ellringham's Paper on the genus Heliconius. 155 



as one species, without further proof, forms with identical 

 genitalia. Among the moths Zygaena lonicerae and 

 Zygaena trifolii in all its forms have the same genitalia, 

 so also have Plusia iota and Plusia pulchrina, yet we know 

 these to be distinct species, the two latter having distinct 

 larvae besides well-differentiated imagines. On the other 

 hand, where differences occur we doubtless have evidence 

 of specific distinctness which in some of the Heliconine 

 instances was not even suspected. 



