MAYER: COLOR AND COLOR-PATTERNS. 215 
diversity of color-pattern and very little variation in venation among 
the species of the Acraeoid group, exactly the opposite condition is 
met with in the Danaoid group, where we find at least twenty 
different types of venation and only two types of color-pattern. 
One of these types of coloration is well exemplified by most of 
the Melinaeas (Fig, 48, Plate 4), and I have therefore called it the 
“ Melinaea” type. The other type is exemplified by most of the 
Ithomias (Figs. 47 and 52) and has been designated in this paper as 
the “ Ithomia” type. In the Melinaeas, it will be remembered, we 
find the rufous and black wings crossed by bands of yellow; while 
in the Ithomias, on the other hand, the rufous and yellow areas have 
become transparent, often leaving the wing as clear as glass, and the 
black, which is so characteristic of the outer half of the wing in the 
Melinaea type, has shrunk away until it has come to lie along the 
outer margin of the wing only. 
By a study of all the genera of Danaoid Heliconidae we gain light 
upon the question of the origin of the “ Melinaea” and “ Ithomia” 
types of coloration. As we have seen (page 198), the Danaoid 
Heliconidae are an offshoot from the great family Danaidae. Indeed,. 
two of the genera, Lycorea and Ituna, are so closely related to the 
Danaidae that Schatz and Réber (85-92) propose to include them 
within that family. There can be but little doubt that Lycorea and 
Ituna are remnants of the ancestral forms which long ago shot off from 
the Danaidae to form the Danaoid Heliconidae ; and it is interesting to 
note, that in these two patriarchal genera we find the two distinct 
types of color-pattern which are exhibited by the Danaoid Helico. 
nidae, for all of the five known species of Lycorea are good examples 
of the Melinaea type (see Lycorea ceres, Fig. 46, Plate 4), while the 
four known species of Ituna all exhibit the transparent, or Ithomia, 
type of coloration. In fact, in their color-patterns the species of 
Ituna remind one of gigantic Ithomias. The species of Lycorea, 
however, are colored very much after the pattern of the Danaidae, 
and indeed they have departed but little from the type of the 
members of the great family whence they sprang. On this account 
I believe that the Melinaea type of coloration, which is so charac- 
teristic of the species of Lycorea, is phylogenetically older than 
the Ithomia type. 
In order to account for the origin of the Ithomia type, we may 
assume that, shortly after the primeval forms of the Danaoid THeli- 
conidae began to segregate out from the Danaidae, the species were 
