but are by far most abundant in intertropical countries. They are more numerous in the new continent than the old, but the difference is by no means considerable. In the former, Brazil alone produces between forty and fifty species; in the latter, the greatest number occur in the islands of the Indian Archipelago, already referred to as the native country of the magnficient Ornithoptera. The continentental parts of India, China, Java, &c. likewise possess many fine species, and a few are found in New Holland. Europe is exceedingly poor in insects belonging to this group, their being only four indigenous kinds. These are P. Xuthus, P. Alexanor, P. Machaon, and P. Podalirius; the two latter, which are the most common, are well known to extend to Britain.
The first species selected to exemplify one of the prevailing forms of this important genus, is
