566 MR. H. W 
tion whose adaptation is complete. As to the fore wings, the vacillating nature of the colours 
is seen in figs. 4, 6, and 8 of Plate LV. in the clearest manner. The hind wings appear very 
peculiar, on account of the milky colour j but this is shown to arise by variation in Tthomia, which 
exhibit all the grades of variation from dusky to white nervures and ground of the hind wing. 
■- 
Nehemia (of authors). — New Granada and S. Brazil. 
ired to show the normal form of the family ( Pieridm, called in England " Garden White " 
Butterflies) to which Leptalis belongs. The contrast in form and colours points to the conclu- 
sion that all the other forms of Leptalis are perverted from the usual facies of the family by long- 
continued process of adaptation to the Heliconidae, in whose company (each species with its 
Heliconian model) they are solely found. 
Fig. 6. Leptalis Theonoe, var. Argochlo'e. — St. Paulo. 
Fig. 6 a. Ithomia Virginia (Hewits.). — St. Paulo. 
The links of modification may be traced also with respect to this apparently distinct Leptalis. 
The shape of the spot of the fore wing is seen to be very variable in figs. 1, 2, 3 of this Plate, 
and in 9 and 4 of Plate LV. 
Fig. 7- Leptalis Amphione, var. EgaSna. — Ega. 
Fig. *a. Mechanitis Polymnia, var. Egaensis. — Ega. 
Fig. 8. Leptalis Orise (Boisduval). — Cupari, 55° W. long.; also Cayenne. 
Fig. 8a. Methona Psidii (Linnaeus). — Cupari ; also Cayenne. 
ERRATUxM. 
At p. 515, after the characters of Family 2. Papilionid^e, insert 
Subfam. 1. Papilionin^:. 
Subfam. 2. PierinjE. 
