586 Mr. J. C. Moulton on some of the principal Mimetic 



as follows, tabulated according to their geographical 

 distribution : — 



1. North-Central America (Guatemala, Honduras, and 

 Nicaragua) ; shown on Plate XXX. 



2. East Brazil ; shown on Plate XXXI. 



3. Upper Amazons (Ega) ; shown on Plate XXXII. 



4. Ecuador, Peru, and Bolivia ; shown on Plate XXXIII. 



The half-tone blocks for these plates were prepared shortly 

 afterwards by Messrs. Andre and Sleigh ; but in the press 

 of other work Professor Poulton has been unable to pub- 

 lish an account of the material or to describe the plates. 

 Early in the present year he invited me to undertake this 

 task, which I need hardly state has proved an extreme 

 pleasure, in view of the exceptional interest of these 

 mimetic associations. I would here like to take this 

 opportunity of recording my sincere gratitude to him, 

 first, for allowing me the privilege of writing this paper, 

 and secondly, for all the kind help and trouble he has 

 shown in assisting me to produce it. The difficulties of a 

 first entomological paper, so alarming to the beginner, 

 have all been made easy by his kindly surveillance. The 

 following associations, although arranged in a diiferent 

 order, are reproduced with but little change from Mr. 

 Blandford's paper (Proc. Ent. Soc. Lond., 1897, pp. xxii- 

 xxvii) : it will be noted, however, that while his combina- 

 tions were wholly composed of butterflies, certain examples 

 of Heterocerous mimics, as well as a few additional 

 Khopalocera, have been incorporated in the tables of the 

 present paper. Mr. Blandford spoke of these mimetic 

 associations as "groups," but I have adopted Professor 

 Poulton's suggestion that they should be called 

 " associations " or " combinations." * 



In the tabular form in which the associations are set 

 forth below, the Ithomiine models are shown on the left 

 and their mimics on the right ; the whole series forming 

 a large combination with a single type of pattern. 



* " Essays on Evolution," 1908, Essay X, p. 293 :— " In this essay 

 the word ' gronp ' is employed to express an arrangement based on 

 affinity, the word ' combination ' or ' association ' to express an 

 arrangement founded on bionomic relationship. Thus a genus or 

 family is spoken of as a group, a set of Miillerian models and mimics 

 as an association or combination." 



