98 LEPIDOPTERA. 



Ukam/ii and Cleopatra formed only one species, since T 

 there found both forms flying together, and was also able to 

 observe afterwards the somewhat diffeient larvae of the two. 



Where on the contrary two similar forms, only dis- 

 tinguished by external and variable characters, like colour, 

 &c. occur exclusively in different localities, the probability is 

 considerable that they are only tvro modified forms of one 

 and the same species. Yet this probability is very difficult 

 to establish to a conviction, and it must, in many cases, be 

 left to the judgment of each individual, whether he will 

 recognise in this or that form only a local variety or a distinct 

 species. One of the few striking cases where we can demon- 

 strate that two species formerly considered as distinct must 

 be united, is furnished by Vanessa Urlicce, L., and Ichnusa, 

 Bon. The last named occurs exclusively in the islands of 

 Sardinia and Corsica, and is only distinguished from the 

 former by a much more fiery-red colour, by the want of the 

 black middle spot of the anterior wings, and by the want of 

 the pale yellowish spot beyond the black dorsal spot (which 

 likewise is sometimes wanting). In reference to the more 

 fiery-red colour, the Sardinian Vanessa lo has it in precisely 

 the same proportions to the German lo, as Van. Ichnnsa to 

 UrticcB. But nobody would therefore account the Sardinian 

 Vanessa lo as a distinct species, and every one must admit 

 that the same climate which gives a redder tinge to the wings 

 of lo might do the same to the wings of JJrticce. 



Moreover nearly the same bright colouring as in Vanessa 

 Ichnusa is met with in the otherwise quite normal V. Urticce 

 of the Balcan Peninsula. With reference to the deficient 

 black middle spot, this is not unfrequently more or less 

 present in Vanessa Ichnusa (especially in the Corsican speci- 

 mens), and on the other hand there are frequent instances 

 where it is rudimentary or altogether obsolete in Vanessa 



