106 



MORPHOLOGY, ETC , OF THE MICROPTERYGIDjE, 1., 



(2) R-2+3 is a simple, unbranched trachea. This is a constant 

 character for the genus. 



(3) The median fork is placed far distad, well beyond half-way 

 along the wing. 



(4) There is no sign of a separate trachea M 4 . In this, Brio- 

 crania agrees with the great majority of Lepidoptera, both 

 Homoneura and Heteroneura, but differs from the Trichoptera, 

 in which all the more archaic genera have M 4 not only present, 

 but quite separated from Cu,.,. 



Forewing of Eriocrania semypurpiwella Steph. Above, the pupal traehea- 

 tiun, ( <54); below, the imaginal venation, ( x 18), For lettering, see 

 p. 136. 



(5) The Cubitus is definitely three-branched, the first dichotomy 

 into Cuj and Cu 2 taking place at about one-fourth of the wing 

 length from the base; further distad, Cuj forks again into Cu Ja and 

 Cu lb . 



This very important character is also to be found in the Mega- 

 loptera, where the comparison with Eriocrania is exact; in the 

 Planipennia, where the branching of Cuj usually consists of a 



