500 MR. H. W. BATES ON THE LEPIDOPTERA 



perform a kind of dance. I believe the parties are composed chiefly of males. The 

 sport begins generally between a single pair: they advance, retire, glide right and 

 left in face of each other, wheel round to a considerable distance, again approach, and 

 so on : a third joins in, then a fourth, or more. They never touch : when too many 

 are congregated, a general flutter takes place, and they all fly ofi", to fall in again by pairs 

 shortly afterwards. The species which I have seen most frequently employed in this 

 way is the Hellcouius Bhea, a glossy blue-black species, with bright yellow belts across 

 its wings. 



The larvae of the two or three species whose transformations I observed feed together 

 in clusters on the leaves of trees of moderate elevation, near the places where the adult 

 uisects are found. 



The majority of the species have very limited ranges. I was surprised, when travelling 

 on the Upper Amazons from east to west, to find the greater part of the species of 

 Ithomice changed from one locality to another, not further removed than 100 to 200 

 miles. For instance, there were 11 of these Ithomice at a place called Eonte Boa, and 

 9 at St. Paulo, 180 miles distant; but only two of the total number (20) were found in 

 both localities. This is remarkable when we consider that the whole of the country of 

 the Upper Amazons is a nearly level plain, uniformly covered with forest, and offering no 

 perceptible difference in soil or other physical conditions. Five only out of the 20 species 

 have been met with in any other part of South America. The areas of distribution of 

 most of the remaining 15 must be, in each case, a very limited tract of country. The 

 species which inhabit other parts of Tropical America must have sunilarly contracted 

 ranges, if we may judge from the collections received in England from different districts. 

 Now, many of these local species have the appearance of being geographical varieties ; 

 I could not help suspecting them to be such when I met with them in nature, the dif- 

 ferences between the forms of one and those of another locality relating in many cases 

 simply to the colours and colour-patterns of the wings. The marks of distinction, how- 

 ever, are in the majority so well defined, so ordinarily common to all the individuals 

 concerned, and there is so generally an absence of connecting links, that they are held 

 on all hands to be good and true species. Moreover, in those cases already mentioned, 

 where a number of very closely aUied species fly together, they keep themselves per- 

 fectly distinct ; there are no hybrid forms (I am speaking of the IthomicB and allied 

 genera), and on observing individuals in copula, I almost always* found the pair to be 

 precisely the same in colours and markings. In the multiplicity, apparent distinctness, 

 and restricted ranges of the species, this group much resembles the family of Humming- 

 birds of the same regions. 



I believe, nevertheless, that the suspicion of many of the species being nothing more 

 than local modifications of other forms has proved to be well founded. Amongst 

 the great number of perfectly distinct and weU-marked species, a few occurred T\'liich 

 showed great variability : these, I think, afford a key to the explanation of the origin 

 of the rest. The details of variation will be given under the head of each species : 



* The exception was in the case of Mechmntis Polymnia, which, as will be seen, on referring to the account of it 

 ill its place, is a polymorphic species, whose local varieties are in an imperfect state of segregation. 



