no John Henry Comstock 



EE. Moths in which cubitus is apparently four-branched. 



F. Humeral angle not strengthened by humeral veins. 

 The frenulum is retained by the males in some genera. The 

 North American forms represent three genera : Drepana, 

 Prionia, and Dryopteris . Family Drepanid^. 



FF. Humeral angle strengthened by the development of 

 one or more humeral veins. There are eight North American 

 genera : Quadrina, Gloveria, Thauma, Clisiocampa, Hetero- 

 pacha, Ariace, Tolype, Gasttopacha. Family IvASIocampid^. 



DD. The Skippers. — These are day-flying Ivcpidoptera, 

 which resemble butterflies in usually holding their wings 

 erect when at rest. They can be recognized b}^ the peculiar 

 venation of the fore wings, in which all of the branches of 

 radius are preserved, and all arise from the di.scal cell. Al- 

 though the frenulum is lost, the frenulum brace (see p. io6) is 

 well preserved in some genera. See discus.sion of the Thyri- 

 didse (p. 107) and compare the figures Plate II, Fig. i, and PI. 

 Ill, Fig. 2. Family Hesperid^. 



CC. Antennae of at least the males with two pairs of pectinations to 

 each segment, excepting the terminal segments in some. 

 D. Antennae of males pectinate for a little more than half their 

 length. Family Ceratocampid^. 



DD. Antennae of males pectinate throughout. 



Family Saturniid^. 

 BOMBYCID^. — The superficial resemblance between this family and 

 the next as shown by the single genus of each known to me [Sericaria 

 and Perophora) is very striking. But a study of the structure of the 

 wings shows marked differences (Figs. 31, 32). Note diiferences in the 

 method of coalescence of the branches of radius of the fore wings, in 

 the course of subcosta of the hind wings, and in the presence of an 

 " intercostal vein." 



Sericaria appears to represent a line of descent quite distinct from the 

 true Saturnians as represented by the American forms. Do the "inter- 

 costal vein " of Sericaria and the caudal horn of its larva have any gen- 

 etic connection with the similar structures in the Sphingidae? This 

 question suggests the desirability of a study of other Asiatic forms allied 

 to Sericaria. It should be remembered that although Sericaria and the 

 Sphiugidffi belong to widely separated divisions of the order, Sericaria 

 stands near the foot of one of them, being very generalized in structure. 

 PEROPHORTD^. — I propose the establishment of this family to receive 

 the genus Perophora, the most generalized of the American Saturnians. 



