BY R. J. TILLYARD. ()4i 



The genus Leto differs from all other Australian genera in the 

 possession of a large raised eye-spot on the forewing, covering 

 the cross-vein r-m, which forms the top of the ridge, and also 

 in the very close similarity in shape between fore and hindwings, 

 as can be seen from Text-fig. 81. 



As a contrast to Leto, I show in Text-fig. 82, the venation of 

 the genus Trictena, of which, unfortunately, I have not been 

 able to obtain pupa?, but only freshly emerged imagines. Here 

 the difference in shape between fore and hindwing is very great, 

 and is typically that of a Heteroneurous rather than a Homo- 

 neurous type. Moreover, the tendency towards heteroneurism is 

 very evident from the fact that there is a vein missing in the 

 hindwing. Mj 2 being a simple vein, and also because, as in the 

 hindwings of Heteroneura, Se and P^ have coalesced near their 

 bases, and run together as a single fused vein to the wing mar- 

 gin. The genus, then, is a living illustration of the manner 

 in which a heteroneurous type can be evolved from a homo- 

 neurous type. It does not, however, indicate the actual line of 

 evolution of the Suborder Homoneura ; because, in their case, it 

 is not the branches of M which become suppressed in the hind- 

 wing, but the branches of Rs. Reduction of the branches of M 

 along the lines indicated in this genus might well have led to 

 the Jurassic fossil family Palaeontinidae (p. 654), which, if Hand- 

 lirsch's restorations be correct, were strongly heteroneurous, but 

 had M reduced to a simple vein in the hindwing. 



Family PROTOTHEORID.E. 



This family was founded by Meyrick (9) to contain a remark- 

 able moth from South Africa, Prototheora petrosema Meyr., 

 which is in some respects intermediate between the Jugo-frenata 

 and the Hepialidae. For material of these rare insects I have 

 t<> thank Dr. L. Feringuey, Director of the South African Mu- 

 seum, Capetown. 



The material sent by Dr. Peringuey, when examined, was 

 found to contain two very distinct species, one of which was 

 probably the same as Meyrick's type, the other very distinct 

 from it. No figures of the venation of these interesting insects 

 have yet been published. Text-fig. 83 shows the venation of the 

 more bluntly winged species (the other has the wings more 

 pointed at apex, with unimportant differences in the venation) . 



The family agrees with the Hepialidae in possessing a true 



