march, 1862. 199 



affirmative one is reached, under which will be found the 

 family to which the specimen belongs. 



To assist the student in discovering the various affirmative 

 and negative categories, those which have reference to the 

 same structural peculiarities are printed in some distinctive 

 type,f and the different categories separated by spaces. He 

 should confine himself to these, until some one is found that 

 corresponds to his specimen, and then continue the investiga- 

 tion by examining the various subdivisions under it, until one 

 is found that is again descriptive of his specimen, and at last 

 the special description indicating the family. Whenever the 

 category disagrees with his specimen, he should, therefore, 

 pass on to the next one in the same kind of typef until one is 

 found that does agree with it. 



Each category includes everything beticeen it and the next 

 of the same value, so that it is useless to look under a dis- 

 agreeing head for anything that characterizes the specimen 

 whose structure does not correspond to it. 



The student must be careful, in detaching the wings from 

 the thorax of a moth, that the little " bristle," which attaches 

 the hind-wings to the anterior pair, is not broken. 



Heterocera. 

 Antenna, setaceous or fusiform, with the apex attenuated 

 (except Castnia, which, however, has a collar to the pro- 

 thorax and the posterior wings a bristle) : wings usually flat- 

 in repose ; hind-ivings generally furnished icith a bristle ; 

 prothorax covered by a collar or patagium. Very often 

 with ocelli or false eyes on the head behind the antennae. 

 Flight diurnal, crepuscular, most frequently nocturnal. 



WINGS NOT PENNIFORM OR FISSURED. 



HIND-WINGS WITHOUT A BRISTLE AT THE BASE OF THE COSTA. 



* Neuration alike in the fore and hind-wings. 

 Costal vein long; a basal spur at base; subcostal 4-branched, 



apical furcate. 

 Wings long, narrow ; discal 3-branched. Median 2-branched. 

 Antenme very short. Epialidae. 



f See note on previous page. H. T. S. 



