the Lepidopterons Family Cossidae. 



159 



the genus presents only minor peculiarities of neuration. 

 The Palaearctic Holocerus, to which the African Rethona 

 is closely allied, is another member of this group with 

 moderately developed tibial spurs. In the hind-wing the 



Fig. 7.- — Dyspessa ulula, 

 Boi-k. 



Fig. 8. — Stygia mistralis, Latr. 



lower branch of the median is often so close to the lower 

 discocellular as to be nearly fused with it. In Dyspessa 

 this has actually occurred, so 

 that the median of this wing 

 appears single, only the upper 

 branch being left. In a third 

 Palaearctic genus of this series, 

 Stygia, the median is unbranched 

 in the fore-wing also, a rare de- 

 gradation of the neuration in this 

 family, though common in other 

 groups. In one specimen the 

 median in the fore-wing is just 

 branched, forming a minute 

 median cell, and I have repro- 

 duced this also in the figure; it 

 is interesting as showing that the 

 median cell has been obliterated in 

 normal specimens by coalescence 

 of the two primary branches of the median. 



Stygia marks the extreme development along one branch 

 of the Cossidae, and we must now hark back to a more 

 primitive Australian genus, Culama, which differs from the 

 ancestral form in only one point of importance, the origin 

 of vein 11 from the areole, which is large. Veins 8 and 9 



Fig. 9, 



< 'ulama austrcdis, 



Wlk. 



