SPECIFIC CHARACTER. _C. alis anticis, supra ferrugineis; posticis rufis, fasciis 3 undatis, nigris, masculis ovatis interstinctis, ornatis._ Anterior wings above ferruginous; posterior rufous, with three waved bands of black, between which are imperfect oval spots. * * * * * The insects of this genus form one of the most singular groups among the Lepidoptera; they are few in number, and confined to the tropical regions of America; flying only during the meridian heat, and then with incredible rapidity: they frequent the narrow inlets of thick forests, occasionally resting, far above the ground, on the trunks of trees. The species here figured is very rare, and came from the Diamond district of Brazil: it is named after the illustrious entomologist who first founded the genus. The bases of the wings beneath are furnished, in the male, with a spiral socket and horny spring, similar to those of the Phalaenidae. * * * * * Pl. 150 [Illustration] SPHINX fasciata. * * * * * GENERIC CHARACTER.--See Pl. 81. * * * * * SPECIFIC CHARACTER. _S. alis anticis subdentatis, supra fuscis, margine postico striga pallida ornato; posticis fulvis, margine nigro; abdomine annuloso, annulis nigris, interruptis, interstitiis albis._ Anterior wings subdentated, above brown, posterior margin with a pale stripe; posterior wings fulvous, margin black; body with black interrupted rings, the interstices white. * * * * * This approaches so near to the Sphinx Alope of Drury, that it is not without hesitation I have ventured to separate them; it will, however, be seen, that neither in his figure or description is any notice taken of the pale testaceous band on the superior wings; the body likewise is described as "encircled with rings of brown and _dark ash_ colour;" in this, the rings are black, on nearly a white ground: the under sides of the superior wings, in Drury's insect, "are spotted along their external edges with long yellowish spots;" in this, they are uniform pale brown. These differences (greatly strengthened by his figure) induce me to consider them as distinct; particularly as both insects appear to have come from Jamaica: the upper side of the antennae are white, the lower brown. Cramer's figure of S. Alope affords little or no clue to illustrate the question. * * * * * SPHINX Leachii. * * * * * _S. alis anticis subdentatis, griseo-fuscis, maculis mediis 3 nigris; posticis fulvis, margine nigro; abdomine griseo, annulis nigris, interruptis._ Anterior wings subdentated, greyish brown, with three medial black spots; posterior fulvous, margin black; abdomen grey, with interrupted black rings. * * * * *