86 
Vi 
Fig. 1. 
Automeris io—A specialised wing with the veins straight, stiff, equidistant ; 
vein VIII of secondaries has been lost by absorption. The ancestral 
form probably possessed this vein. Cells closed, cross-vein transverse. 
The median branches retain their primitive generalised position. Vein 
IV 2 is central on primaries, on secondaries (as usual) it has slightly 
yielded to radius. Vein IV 1 remains on cross-vein close to radius. If 
this type had descended from Hemileuca-like ancestry this position of 
IV 1 could not possibly have been acquired. Vein III 1 + 2 is further 
advanced than in Hemileuca, but III 3 + 4 has a longer fork, hence 
here more generalised. The absence of any intention to form a stem 
for the two upper branches of media characterises this type. Compare 
with Fig. 3, Aglia tau, and contrast with Fig. 2, Hemileuca maia. This 
wing is more specialised than Hemilewca from the point of origin of 
III « + 2, being farther removed from base of wing, and the dis- 
appearance of VIII on hind wings. It should therefore, according to 
Dr. Dyar’s classification, be developed from it, which I hold to be an 
impossible process. 
