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Genus THALIURA.
The genus to which we have assigned the above name has been hitherto blended with the Uraniæ. It is doubtless very closely connected with these insects; but the differences both in the appearance of the perfect insects and the respective caterpillars, render it expedient that they should be separated. The character by which it and Urania are widely separated from all others, is the form of the antennæ, which are filiform nearly to the middle, where they thicken a little, and from that gradually narrow to a point. The palpi are lengthened and slender, having the second joint greatly compressed, the terminal one more slender, nearly cylindrical, and naked. There is no closed discoidal cell in any of the wings, and almost all the nervures diverge from the base. Not many different kinds are known, and, with one exception, they are natives of America and the West Indian Islands. Their splendid tints of golden green arranged in transverse bars, render them perhaps the most chastely beautiful insects that exist, and has caused them to be named Emerald Butterflies in this country. Sometimes also they are called Pages. They fly so high in the air and with so much velocity, that it is nearly impossible, Madam Merian informs us, to catch them,
