266 MK. J. WATSON ON THE PLUMULES OR 



and they bear a very strong similarity to those of the 

 Heliconidce, the insects themselves being also alike. A 

 comparison of Heliconia Vesta and Eueides Tholes would 

 induce a casual observer to regard them as almost identical ; 

 but Mr. Hewitson* has pointed out " a difference in the 

 position of the discoidal nervuxes of the posterior wing^ 

 as well as in the orange rays which proceed from the base 

 of the posterior wing /^ and he well says, " If a butterfly 

 or a genus resemble another (though placed systemati- 

 cally at a distance from it), let it be in colour or in form, 

 it may be expected to resemble it in other characteristics.^' 

 The plumule of Eueides Tholes you will see on PL V. 



Colcenis. — Found in 5 species, two of the forms being 

 shown on PL V. fig. 6. 



Agraulis. — Found in 3 species, introducing a very dis- 

 tinct type, which we shall see is, as it were, played upon 

 and repeated with variations in other genera. PL VI. 

 fig. 7. 



Terinos. — On the two species of this genus which I 

 possess there is a very peculiar pear-shaped scale, not, 

 however, I think, a plumule. I notice this genus here in 

 its place because it possesses hairs of a bifid form at the apex, 

 of a character similar to some which will presently be 

 noticed under the genus Argynnis. 



Lachnoptera. — This genus consists of a single species, 

 " lole ;" and its very peculiar scale is shown on PL VI. 

 fig. 8. It was noticed by Doubleday, who regarded it as 

 probably of a sexual character, although he had never 

 seen a female ; nor have I. He describes it as " a hair- 

 like scale, terminating in a vane like the feathers of the 

 raquet-tailed humming-birds.^' 



Argynnis. — Plumules found on 15 species. They have 

 often been noticed by microscopists ; and two were figured 

 * Joui'n. ol'Enl. vol. i. p. 156. 



