feY R. J. TILLYARD. 



171 



venation " based on the Protomecopterous wing-type, and solved 

 by means of the trigamma-key. 



Two of the main objects of this paper are, (a) the establish- 

 ment of the homology of each Lepidopterous vein with a vein 

 of the archaic Protomecopterous wing-type, and hence with a 

 corresponding vein in all other Ordeis of Insects: (6) the estab 

 lishment of correct homologies between the veins of the fore 

 and hindwings in Lepidoptera. Tlie former object is illustrated 

 in Text-Kgs. 1-6. The latter may be shown by drawing up a 



Cuj^+N^ 



^A „ 



Tcxt-ti<^6.■ 



Text-fiK.7.t 



table showing the true homologies of the veins and their desig- 

 nations in fore- and hindwings under (1) the numerical system 

 in use at the present time by British Lepidopterists, and (2) the 



Staudinger-Schatz notation. 



* Wing-venation of the butterfly Bajjfo/a corinua MacL, (from Water- 

 house and Lyell). The Lepidopterous cell (L) is completely formed in both 

 M'ings. An example of heteroneuric venation. 



t Hampson's diagium of typical Moth- venation (from Sharp). The 

 formation of the radial branches towards apex of forewing has been cor- 

 rected (in many forms dc closes completely up). Heteroneuric venation. 



