112 



MORPHOLOGY, ETC., OF THK MICROPTERYGIDjE, 1. 



which the basal part is formed from 2A, and the middle con- 

 necting piece by a longitudinally placed cross-vein, the inter- 

 anal (ia). The distal end of 2A descends transversely to the 

 wing- border, and thus resembles a cross- vein. 



Thus we see that the cubital and anal portions of the fore- and 

 hindwings in Eriucraaia are really very different, though there 

 is a superficial analogy between non-homologous parts; as, for 

 instance, between the curved distal part of 2A in the forewing 

 (where it joins up with 1 A) and the inter-anal cross- vein of the 

 hind; and again, between the sub-anal cross-vein of the forewing 

 and the descending distal portion of 2A in the hind. 



Text-fig. 4. 

 Portion of basal tracheation of hindwing of the pupa of Eriocrania semi- 

 purpurella Steph., to show the cubital fork (contrast its position with 

 that of the forewing) and the tortuous course of trachea IA, with the 

 manner of formation of the fused vein Cu 2 + IA. ia, inter-anal cross- 

 vein; pa, posterior ar cuius; ( x 165). 



It should be noted that the subcostal vein is proportionately 

 shorter in the hindwing than in the fore, ending only a little 

 beyond half-way along the costal border The costal space is 

 proportionately narrower. The pterostigmatic region is longer 

 and narrower, and not crossed by a vein R u . The radio-median 

 cross-vein is plainly visible; whereas, in the forewing, it is lost 

 in the thvridium, The imaginal venation of the hindwing is 



