Evolutioyi and Taxonomy 99 



EE. Butterflies in which cubitus is apparently three- 

 branched. 

 F. Butterflies exhibiting no tendency to abortion 



of the fore legs. Family Pierid^. 



FF. Butterflies exhibiting a marked tendency to 



abortion of the fore legs. 



G. Family lyYC^NiD^. 



GG. Family Nymphalid^. 



A. SUBORDER JUGATE 



This suborder includes those moths in which the two wings 

 of each .side are united by a membranous lobe, the jugum, 

 borne at the base of the inner margin of the fore wings (Fig. 

 27, j), and in which the anal area of the hind wings is reduced 

 while the radial area is not. The most available recognition 

 character is the similarity in venation of the two pairs of 

 wings ; radius being five-branched in the hind wings as well 

 as in the fore wings. 



B. THE MACROJUGAT^. 



Moths of medium or large size. The mouth-parts are 

 aborted, and correlated with this there persists a comparatively 

 generalized condition of the wings, which is shown by the 

 absence of a jugum plate. The larvse are wood-borers. This 

 division is represented by a single family. 



Family Hepialid^. 



BB. THE MICROJUGAT^. 



Moths of minute size. Mouth mandibulate, with both 

 mandibles and maxillae fitted for mastication. This is doubt- 

 less the most generalized form of mouth-parts preserved in 

 this order. Correlated with the presence of functional mouth- 

 parts, these moths show a higher specialization of wing 

 structure than exists in the Hepialidse ; there being a plate- 

 like organ at the base of the costa of the hind wings, the 

 jugum plate, and a series of spines ; both of which act with the 

 jugum in assuring the synchronous action of the two pairs of 



