Page:The naturalist on the River Amazons 1863 v1.djvu/282

 The case was furnished by certain kinds of handsome butterflies belonging to the genus Heliconius, a group peculiar to Tropical America, abounding in individuals everywhere in the shades of its luxuriant forests, and presenting clusters of varieties and closely allied species, as well as many distinct, better marked forms. The closely allied species and varieties are a great puzzle to classifiers; in fact, the group is one of those wherein great changes seem to be now going on.

of the group is the H. Melpomene of Linnæus. This elegant form is found throughout Guiana, Venezuela, and some parts of New Granada. It is very common at Obydos, and reappears on the south side of the river in the dry forests behind Santarem, at the mouth of the Tapajos. In all other parts of the Amazons valley, east-