286 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Plate 6 is intended to exhibit the characteristic color-patterns 
found in the Melpomene group and in the genus Eueides. Fig. 70 
represents H. melpomene, and Fig. 71 its near ally, H. callycopis, in 
which the red area of the fore wing has become broken up, and some 
red spots have made their appearance near the base of the hind wing. 
In the next variety of Id. melpomene, Id. cybele (Fig. 72), it is 
remarkable that the pattern of the fore wing has come to resemble 
the Sylvan us type, and is identical in general plan of coloration with 
the fore wings of the Melinaeas or Mechanitis (see Figs. 84 or 85, 
Plate 7 , or dbgs. 92 or 94, Plate 8 ). In its close ally, dd. thelxiope 
(Fig. 73), a still nearer approach to the Melinaea type has come 
about by the development of a black band across the middle of the 
hind wing, and one has only to imagine a general fusion of the seven 
club-shaped red stripes of the hind wing in Fig. 73, Plate 6 , in order 
to produce exactly the Melinaea type as exhibited, for example, by 
Eueides cleobaea (Fig. 78). In this connection it is worthy of note 
that Bates (’62) showed that II. thelxiope was derived from dl. 
melpomene, there being between the two many intermediate forms. 
H. vesta (Fig. 74) is evidently a close relative of Id. thelxiope, 
and what is still more worthy of note is, that it is almost identical in 
the general effect of its color-pattern with Eueides thales (Fig. 75)1 
The yellow spots upon the fore wing of E. thales are, however, duller 
in hue than are those of H. vesta, and the insects are somewhat 
different in size, Id. vesta spreading 78 mm., while E. thales spreads 
only 66 mm. It will be noticed that the chief difference between 
the color-patterns of these two species lies in the fact, that, while the 
black stripes of the hind wings in H. vesta lie along the nervures, in 
Eueides thales they occupy the middle of the cells themselves. The 
general resemblance of the two color-patterns may of course be 
merely accidental. An easy explanation, however, is afforded by 
the theory of mimicry, for the two species look very much alike 
until one subjects their color-patterns to close analysis, when 
remarkable differences appear. E. thales (Fig. 75) may have been 
derived from some such form as E. mereaui (Fig. 76), for one has 
merely to imagine a greater development of the black and a general 
deepening of the rufous upon the hind wing of E. mereaui to make 
it resemble E. thales quite closely. Finally, in E. aliphera (Fig. 77) 
the black serrated border of the hind wing is still more reduced, and 
the black stripe which crosses the cell of the fore wing inE. mereaui 
is not present. 
