260 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
observed that this crescent follows the general law and is bilaterally 
symmetrical about the usual axis. 1 
Fig. 9 shows the law of repetition of some very complex spots, each 
being bilaterally symmetrical. It is found in Parthenos gambrisius. 
Figs. 10 and 11 represent Ornithoptera urvilliana and O. priamus 
respectively. In Fig. 10 we see an instance of a spot within a spot, 
and in Fig. 11 an even more complex case, for here there are three 
systems of spots one within another. 
Fig. 12 represents the marginal markings found in Ilestia jasonia 
and Fig. 13 Hestia leuconoe var. clara. These two examples are 
intended to illustrate -the fact, that, although the markings are 
situated upon the nervures, they are bilaterally symmetrical not 
about the nervures as axes, but about the usual axis passing midway 
between the nervures. In Fig. 12 it will be seen that the two 
curved markings situated upon nervures l b and 2, and projecting 
into cell I c , are bilaterally symmetrical only in reference to the axis 
through the middle of the cell. 
In allied species the spot situated upon nervure l b is often absent. 
The system of markings is therefore undergoing degeneration at this 
end (cf. Fig. 13, cell I c ). The curved mark upon nervure 5 (Fig. 
12) projecting into cell Y is plainly symmetrical with respect to its 
fellow in the opposite side of cell Y, and not with its near companion 
which projects into cell IY. The same is also true in the case of the 
spots in cell VI. 
In Fig. 13 the spots appear at the first glance to be bilaterally 
symmetrical about both nervures and centers of cells, but in cell IY 
the marking situated on nervure 4 does not quite reach to the cen¬ 
ter, and it is interesting to observe that its fellow on nervure 5 also 
falls short of reaching the center and is therefore symmetrical with 
respect to the other curved spot in cell IV. This case also furnishes 
an instance of a break in the middle of a linear series. 
Fig. 14 is taken from the under surface of the hind wing of 
Papilio emalthion. It serves to illustrate the fusion of two orig¬ 
inally separate rows of spots. In this case the crescent-shaped spots 
above have fused with the rectangular ones below, so as to inclose 
a portion of the ground color of the wing. Sometimes two rows of 
1 A very beautiful exception (Fig. 10, Plate 2) to this rule for the crescents found in eye- 
spots is seen in the under surface of the fore wing of Missanga patinia Moore. It will be 
noticed that the large black crescent found in this beautiful eye-spot is 90° away from its 
usual position. This is the only exception of the sort known to me. 
