It is questionable whether this figure represents the Phalæna senatoria or pellucida of Abbot and Smith, by whom the transformations of both species have been illustrated; Smith citing Drury's figure with doubt, as belonging to pellucida. I have much pleasure in adopting the present well-marked genus proposed by Dr. Thaddeus W. Harris, one of the most distinguished American entomologists, in the appendix to the work above referred to; and respecting which I am indebted to that gentleman for the following communications:--"The male of Dryocampa senatoria, of Abbot and Smith, has the basal half of the antennæ pectinated on both sides, and the apex simple, as in Bombyx (Cerocampa, Kirby; Ceratocampa, Harris's Cat.) regalis and imperialis; and as they are described to be in the genus Zeuzera. The larvæ are naked, striped, rigid, with acute tubercles, and two thread-like horns on the second segment. They devour the leaves of forest trees, particularly oaks, and enter the earth to become pupæ. The edges of the segments of the pupæ are denticulated. On account of these peculiar characters, I have ventured to assign to this a new generical name; under which will be included also Bombyces pellucida, and Stigma, Fabr., figured in Abbot and Smith's Lepidopterous insects of Georgia; together with B. rubicunda, F. all of which are now found to inhabit Massachusets." In addition to the characters mentioned by Dr. Harris, the peculiar form of the posterior wings of the males of these moths may also be noticed, and which are of a triangular form, somewhat like those of Erycina menetas (see vol. 3. pl. 8. fig. 3.), but extending to the extremity of the abdomen. This genus is not far removed, in its natural affinities, from that of Ceratocampa, (see vol. 1. pl. 9.) ÆGOCERA AMABILIS. Plate XIII. fig. 3. ORDER: Lepidoptera. SECTION: Crepuscularia? FAMILY: Sesiidæ, _Steph._ GENUS. ÆGOCERA, _Latr. Boisduval._ ÆGOCERA AMABILIS. Alis anticis rufis, maculis (nigro marginatis) margineque interno, albidis; posticis fulvis maculâ discoidali margineque postico nigris. (Expans. Alar. 1 unc. 6 lin.) SYN. Phalæna (Noctua) Amabilis, _Drury_, _App. vol._ 2. Ægocera Amabilis, _Boisduval Hist. Nat. Lepid. pl._ 10. B. _f._ 6. HABITAT: Coast of Guinea. _Upper Side._ Head brown. Antennæ filiform. Thorax and abdomen yellow brown. Superior wings fine darkish red, with several yellow spots thereon of different shapes, each encircled with black; the posterior and external edges having yellow margins. Posterior wings deep yellow, inclining to {26}orange, with a black oval spot near the middle of each. Along the external edges is a black margin, reaching from the upper to the abdominal corners; the upper edge being scolloped.