Dimorphism and Polymor2:)hisvi in Butterfiies. 31 



is the black male of Lycsena Violacea, one of the poly- 

 morphic forms of Lycsena Psendargiolus, which is found 

 in this spring brood in Virginia and the South. 



This case is especially remarkable in being the only 

 example so far known of partial dimorphism in which the 

 male instead of the female departs from the type. 



I have already referred to the fact in treating of sexual 

 dimorphism that in some species of the germs Colias, the 

 male is yellow and the female white, but in quite a 

 number of other species and among them our common 

 Sulphur Butterfly, Philodice, there are two forms of 

 female, one yellow like the male, and the other albino, 

 though the albino specimens are rare, but no case of an 

 albino male is known. 



Partial dimorphism is not by any means common, 

 and the only other instance in our butterfly fauna which 

 is familiar to me is that of Pamphila Hobomok which has 

 two forms of female, and was therefore nicknamed the 

 Mormon by Dr. Sc udder, one being largely tawny like 

 the male, and the other very dark in colour, and formerly 

 supposed to be distinct, was named Pocahontas. 



Among the species in which complete dimorphism 

 occurs may be mentioned several species of G-raptas, 

 popularly called Comma Butterflies from the silvery 

 mark resembling a comma on the underside of the hind 

 wings. 



These are Grapta Interrogationis with its two forms, 

 Pabricii and Umbrosa, Grapta Comma with its two seasonal 

 forms, Harisii the autumnal and spring form, and Dryas 

 the summer form. 



Grapta Satyrus, a most interesting species, having its 

 home or metropolis in the far west where it is dimorphic 

 with a second form named Marsyas, but occurring 

 extremely rarely in the east where the form Marsyas 

 has never been found, and Grapta Silenus another western 

 species with a dimorphic form, Oreas. 



