500 MR. H. W. BATES ON THE LEPIDOPTERA 



))erform 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 ronnd 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 off", to fall in again by pairs 

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

 way is the Ildicoiiius lilieu, a glossy blue-black species, with In-ight yellow l)elts across 

 its ^\angs. 



The larva? 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 

 insects are found. 



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

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

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

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

 9 at St. Paulo, 180 miles distant ; but only two of the total num1)er (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 

 perceptilde diiTerencc in soil or other physical conditions. Five only out of the 20 species 

 have been met with in any other part of Soutli America. The areas of distriliution of 

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

 species which inhal)it other parts of Tropical America must have similarly 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 l)etween 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 allied species fly together, they keep themselves per- 

 lectly distinct ; there are no hybrid forms (I am s2:)eaking of the Ithomice and allied 

 genera), and on observing individuals hi copula, I almost always * found the pair to l)e 

 pi'ecisely the same in colours and markings. In the multiplicity, apparent distinctness, 

 and restricted ranges of the species, tliis grouji much resembles the fiimily of Humming- 

 birds of the same regions. 



i believe, nevertheless, that the suspicion of many of the species being nothing nion' 

 tlmn local modilieations of other forms has proved to be well founded. Amongst 

 the great number of ])erfectly distinct and well-marked species, a few occurred which 

 showed great vai'iability : these, I think, afTord a key to the explanation ol" the origin 

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



• Tiic i'\cc]ili(in uas in liii' cusc of Mcr/id/ii/i.s I'o/i/iii/iic/, wlni'li, as will l>i' seen, (in LrlVrriiij; to llu' acrtnuit of it 

 in Its |ilai-c, is a ]iolviiior|iliic s|ii'c'it's, wliosc local vaiii'tics arc in an ini|icrfi"ct state of segregation. 



