How then can Mr. Sudder claim that this feeble relic of the tertiaries, stranded, as he tells us, on the loftiest peaks at east and west at the close of the glacial period, unchanged in all respects since that, its imago showing itself but onec in two years, the individual living at most but a few days, always in tribulation and peril, saved only from extinction by its acquired habits of dropping into a crevice, or of clinging to the rocks by the feet, its wings of sacrcely any use whatever, but a constant source of danger—that this miserable creature stands at the head of its genus, its sub-family, its family, of the American fauna, and in fact of the world, the ideal butterfly!*

1. Nematusocreatus.—♀. Testaceous or honey-yellow; length, 0.35 inch.

Head polished, sutures behind ocelli well defined; ocelli in a slightly curved line with the lower one on the rim of a large shallow basin; face below antennæ, another between them, and one on edge of occiput; antennæ slender, two-thirds as long as body, black with basal joints paler; joints three and four subequal; five shorter.