272 AMERICAN MICRO-LEPIDOPTERA. 



Forewings with 5 absent; hindwings with 6 absent. 



Vein 11 of the forewings absent; posterior tibiae without hairs. 



Subgenus Porphyrosela. 

 Vein 11 of the forewings present ; posterior tibiae with appressed hairs. 



Lithocolletis Kb. 

 Forewings with 5 and 6 stalked ; hindwings with 5 and 6 stalked. 



Subgenus Cremastobombycia. 



MTHOCOLL-ETIS Hiibner. 



Characters of Lithocolletis as given in Meyrick's " Handbook of 

 British Lepidoptera," 1895, p. 733. 



Head (Plate XX, Fig. 9). Face smooth, crown rough tufted. 

 Labial palpi porrected or drooping, moderately long, pointed. Max- 

 illary palpi rudimentary. Tongue moderate. Antennse nearly 

 attaining the wing length, simple in male, basal joint thickened, 

 bearing a pecten. 



Forewings elongate, lanceolate, acuminate. 



Hindwings about one-half the breadth of the forewings, linear 

 lanceolate, cilia 4-5. 



Venation (Plate XX, Figs. 1, 2, 3, 4, 5). Forewings: Ib simple, 

 3-5 absent, 7 to costa, 8 absent, 10 absent. Hindwings : 3 absent, 

 4 absent, transverse vein absent between 2 and 5, 6 absent. 



Posterior tibiae, with appressed hairs. 



Our representatives fall naturally into two distinct and well de- 

 fined groups, identical, however, in structural details of the imago. 

 The first, comprising those species having a cylindrical larva, agrees 

 closely with the European species in embryonic stages and in type 

 of markings of the imago. The second group includes all those 

 species having a flattened larva, and is characterized by a definite 

 type of wing marking. 



Most of the species are included in this division, which is well 

 represented in all parts of the country. A very few of the species 

 occur throughout the entire country ; others are of comparatively 

 wide distribution ; a few appear to be confined to a very limited 

 area. 



The following characters will separate the two groups : 



Larva cylindrical; white streaks and fasciae dark margined internally. ..Group I. 

 Larva flattened ; white streaks and fasciae dark margined externally.. .Group II. 



