XXXVili MEMOTR. 
commonest Ithomia of St. Paulo; on the wing their resemblance is much more 
striking than when in the cabinet. In fact I was quite unable to distinguish 
them on the wing; and always on capturing what I took for an Ithomia and 
found when in the net to be a Leptalis mimicking it, I could scarcely restrain 
an exclamation of surprise. One species imitates exactly I. Cidonia, another 
I. Onega, which is more abundant at St. Paulo than at any other place, and 
a third another unnamed species of Ithomia, also one of the most abundant 
species. The resemblance between Leptales and Ithomiz, two groups of 
Diurnes much more widely separated than they appear in our classifications, 
is repeated in the case of a group of Bombycide moths, of which there are at 
least two genera imitating the Ithomiz and the larger Heliconiz. One of 
them, which I saw first at the British Museum, exactly imitates Ithomia Flora ; 
at Ega there is one imitating in the same way Ithomia Fluonia of the same 
locality. At Fonte Boa appears another, standing in the same relation to 
I, Ailia of the same place, and at St. Paulo there are others occurring 
simultaneously with the peculiar Ithomiz of the district. These analogies 
to me appear amongst the most beautiful phenomena in nature.”’ 
The full title of the paper is “ Contributions to an Insect Fauna 
of the Amazon Valley. Lepidoptera: Heliconide.” By Henry 
Walter Bates, Esq. (Communicated by the Secretary.) Read 
November 2Ist, 1861.* The interesting and important character 
of the phenomena described in the paper, and the relatively small 
space given to them in the Naturalist on the Amazons, may render 
some account of the matter not out of place here ; the more so as 
the paper itself is buried in the well-nigh inaccessible memoirs of 
a learned society. The literature of the subject which has followed 
the publication of that paper is too extensive to be touched upon 
here. 
After describing the natural history of the Heliconide, a family 
of brilliantly-coloured butterflies which abound in the American 
tropics, Bates referred to the mimicking of which a large number of 
species are the objects. “Mimetic analogies, it is scarcely necessary 
to observe, are resemblances in external appearance, shapes, and 
colours between members of widely distinct families; an idea of 
what is meant may be formed by supposing a pigeon to exist with 
the general figure and plumage of a hawk.’ t 
A large number of species are accompanied in the districts which 
they inhabit by other species which counterfeit them. For example, 
in districts where an /¢homia abounds, a Leftalzs will, as remarked 
by Bates in his letter quoted above, be found mingled in the same 
* Transactions of the Linnean Soctety of London, xxiii., part 3, pp. 495-566, 1862, 
With Plates. 
Tt Zap 502. 
