212 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



Plate 6 is intended to exhibit the characteristic color-pattei'ns 

 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 H. melpomene, II. cybele (Fig. 72), it is 

 remarkable that the pattern of the fore wing has come to resemble 

 the S3'lvanus 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 Figs. 92 or 94, Plate 8). In its close ally, H. 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 F'ig. 73, Plate 6, in order 

 to })roduce 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 H. thelxiope Avas derived from H. 

 melpomene, there l>eing between the two many intermediate forms. 



H. vesta (Fig. 74) is evidently a close relative of H. thelxiope, 

 and what is still more worthy of note is, that it is almost identical in 

 the general effect of its color- jjattern with Eueides thales (Fig. 75)! 

 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 m size, H. vesta spreading 78 mm., while E. thales spreads 

 only G6 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 in E. mereaui 

 is not present. 



