338 William T. M. Forbes 



labials moderate to long, upturned, without bristles, with the third 

 joint long, and smoothly scaled; almost always straight and fusiform; 

 tongue present, sometimes naked. Eyes good-sized. Thorax with scaly 

 vestiture; legs various, typically smooth-scaled. Venation but little 

 reduced; fore wing with R 3 running to outer margin; usually with all 

 veins separate, and usually with a stigma along costa from tip of 

 Sc to R x ; hind wing with R and M ± well separated, except in Ceros- 

 toma; M 1 and M 2 often stalked; 1st A distinct in both wings. 



Larva quite variable (figs. 205-211) but always with seta beta on 

 the cervical shield farther from the middle line than alpha, setas iv 

 and v widely separated on the abdomen, and the prespiracular wart 

 bearing three seta?. 



Egg, so far as known, of flat type and normal. Pupa obtect; with 

 rnaxillary palpi distinctly preserved; with pilifers represented by dis- 

 tinct lobes only in the genus Atteva; front femora exposed except in 

 Scythris. The pupa? are less heterogeneous, apparently, than the larva?, 

 except for Scythris and Atteva. 



The family as here limited is far from homogeneous : Yponomeuta, 

 Prays, and Swammerdamia form the Yponomeutinas, and are close rela- 

 tives ; Plutella, Cerostoma, and Trachoma form a second group : Plutel- 

 linse ; and Argyresthia and Zelleria, a third. The remaining genera are 

 entirely isolated. Acrolepia partly fills the little gap between Argyres- 

 thia and the Tineida?; Atteva is a fair Pyralid in the pupa, though 

 nearly a normal Yponomeutid in the adult, and with several exotic 

 genera may constitute the transition from the Tineids to the Pyraloids 

 and Macros. Scythris shows characters of the Gelechioidea, and may 

 not belong here ; Epermenia seems to belong in this region but is gen- 

 erically isolated. 



Besides our miscellaneous . assortment, several other types occur in 

 Europe and in the tropics, some of the latter hardly to be distinguished 

 from the Zygamicla?, and others connecting the iEgeriidas and Heliod- 

 inida? with this family (Tina?geriida?). The Tina?geriidas, as usually 

 delimited, are mostly placed by Meyrick in the Heliodinidffi. 



1. PRAYS Hiibner 

 (Yponomeuta, in part) 



Similar to Yponomeuta, but with fully scaled wings. Rj and R 5 of the fore wing 

 typically stalked, and basal fork of A very large; our species with the venation of 

 Yponomeuta, R 4 and R 5 being either stalked or closely approximated. 



1. P. atomocella Dyar. Much like Y. midtipunctella, black dots larger; abdomen, 

 fringe, and hind wing dull salmon color, duller in male. 20 mm. (diapkorus Wal- 

 singham; Yponomeuta Walsingham and Dyar.) 



April. Larva on Ptelea. 



Southern Ohio; Illinois; Texas. 



