NORTH AMERICAN LEPIDOPTERA. 181 



Suborder PBENAT^. 

 Frenulum usually distinct, siugle in % , usually divided and shorter iu 9 '■ rarely 



abortive Frenulum conservers. 



Frenulum absent, or very rudimentary; replaced by an expanded area at base 

 of secondaries, often containing supplementary humeral veins. 



Frenulum losers. 



The frenulum conservers are well distinguished in general ; but 

 several genera occur iu which the frenulum is much reduced or even 

 absent, while in some families included in the frenulum losers there 

 is a rudimentary frenulum. These divisions of the Frenatae do not 

 represent separate lines of descent, as is the case in the division into 

 suborders since the Lasiocampidse are separated from their allies in 

 the Arctiid series. 



The Frenulum conservers. 



Primaries with two, or secondaries with three anal veins, usually complete: 

 median often well preserved..... Generalized frenulum conservers. 



Primaries with one, and secondaries with not more than two anal veins, except 

 rarely traces of a third Specialized frenulum conservers. 



These divisions are fairly well marked. The Castniidse, Cossidse, 

 Eucleidse {= Limacodidse), Pyromorphidse, Megalopygidae (= La- 

 goidse), Psychidse and many of the microlepidoptera fulfill the char- 

 acters of the first division ; but this does not appear to be the case 

 with all the microlepidoptera, nor with the Sesiidse. On the other 

 hand, our species of Phryganidia (Dioptidse) shows a portion of a 

 third anal vein on the hind wings. 



The families intended to be included by the term " specialized 

 frenulum conservers" may be separated by the following table: 



Secondaries without distinct intercostal cell. 



(Jubitus of primaries apparently 4-branched. 



The radius and subcosta of secondaries united for about one-third the 



length of cell or more. 



These veins completely coalesced to tip EUCHBOMIID^. 



Not corupletely coalesced (apparently so in a few instances). 



( ARCTIID^. 



1 LITHOSIID^. 



The radius and subcosta free toward base, except in a few instances. 



Vein Vi arising close to, or in conjunction with radius on secondaries. 



Cubitus of secondaries apparently 4-branched ; % autennje pectinate. 



f PERICOPID^. 



1 LIPARID^. 



Cubitus of secondaries 3-branched, or 4-branched ; antennae often 



, ,,. e. 4. ( NOCTUID^. 



simple; ocelli often present - 



i AGARISTID^. 



TRANS. AM. ENT. SOC. XXI. JUNE, 1894. 



