116 PROCEEDINGS OF THE NATIONAL MUSEUM ▼<«* » 



were studied, and to ascertain intraspecific variation of larval, vena- 

 tional, and genitalia structures approximately 300 microscopic slide 

 mounts were prepared. The number of slide mounts for a species 

 varies from 1 to 36, depending on the amount of material on hand. 



Because there has been much confusion of the species in the litera- 

 ture, citations for food plants and localities are based entirely on labels 

 associated with specimens examined by the author, unless specified 

 otherwise. Much of this confounding of the species has probably been 

 due to three factors: (1) Close similarity of the species, (2) ex- 

 tremely great intraspecific variation, and (3) lack of sufficient material 

 to indicate or determine the range of intraspecific variation. The 

 author strongly suspects that extensive collecting and rearing will, in 

 the future, make untenable some of the forms that it now appears de- 

 sirable to retain as food plant or geographical varieties. 



The following brief diagnosis of faxciaria (Linnaeus), the genotype 

 of Therina, is offered for comparative purposes: Male antenna bi- 

 pectinate to apex; female antenna simple. Fore wing (fig. 3) with 12 

 veins, 10 and 11 from the cell ; without areoles. Male genitalia (fig. 4) 

 without gnathos; harpe with middle narrowly constricted, a costal arm 

 from near base; vinculum well developed, narrowly extenuated; furca 

 simple; aedeagus bifurcate. Female genitalia (fig. 20) with signum a 

 small, weakly sclerotized plate. Larva with prolegs on fifth abdomi- 

 nal segment. 



All the American forms treated here differ from fasciaria in the 

 following respects: Fore wing (figs. 1, 2) with two areoles. Male 

 genitalia (fig. 7) ; harpe simple, not constricted at middle, costa with- 

 out an arm ; vinculum not extenuated ; aedeagus simple. Female geni- 

 talia (fig. 21) with signum a strongly sclerotized stellate, serrate or 

 spinose plate. Larva without prolegs on fifth abdominal segment. 

 In genitalia, they resemble species of Nepytia Hulst and CingiUa 

 Walker. CingiUa, however, has a vestige of vein 5 at the margin of 

 the hind wing and species of Nepytia are distinguishable by the cren- 

 ulate or denticulate character of the transverse lines of fore wing. 



Few studies of a revisional nature treating this subfamily have 

 appeared, and though the four genera discussed in this paper do not 

 constitute a recognized or definable group of supergeneric rank the 

 following characters are common to the group and are cited to avoid 

 repetition in generic descriptions : Male antennae bipectinate, plu- 

 mose; pectinations not clavate, sometimes terminating before apex. 

 Labial palpus slender, extending but slightly beyond the front ; front 

 evenly rounded, scales closely appressed. Fore wing (figs. 1, 2) broad ; 

 transverse posterior line, if present, from costa well before apex; 12 

 veins and 2 elongate areoles; vein 12 anastomosing with 11 and then 

 separate to costa; 10 and 11 from cell; 8 and 9 stalked; 2 from cell 



