AMERICAN LEPIDOPTERA. 207 



Iii Heliothia paradoxus the neuration of the 9 > s normal ; of the % 

 aberrant. This aberration I have not given a generic value, and have 

 discarded Heliochllus which was based on it. This T have done because 

 the aberration is found in one sex only, the 9 being a true Helioihis, 

 and sexual characters should not in my opinion be accorded a generic 

 value ; and also because it is an aberration only, entirely out of harmony 

 with the variations elsewhere found in the venation of the Nbctuidae. 

 The abdomen of the 9 sometimes has the oviduct more or less ex- 

 truded, but no generic value can be attributed to this character for it 

 grades so insensibly from one extreme to the other that it would be a 

 matter of great difficulty if not impossibility to limit a genus thus based. 

 The genitalia of the % I have not examined for the following reasons : 

 first, they can never have a generic value ; second, I did not need them 

 for sub-divisions, and in the third place there were many species of which 

 I have seen the 9 on ty- 



The legs and more especially the tibiae have furnished bases for gen- 

 eric divisions. Species with spinose tibiae I have uniformly separated 

 from those not so armed, though there were described in MeUcliptria 

 species with and without this distinction. 



The anterior tibiae vary very decidedly and I have given the variations 

 a modified generic value. Those species of MeUcliptria which have the 

 anterior tibia not abbreviated, and - merely terminated with spinules I 

 separate from that genus. 



It was with that group having the anterior tibiae abbreviated and heavily 

 armed that I had the greatest difficulty, the question being whether the 

 variation had generic value, and if so to what extent. The negative 

 seemed the safer and I have therefore followed that course. Still there is 

 no genus the species of which differ very widely in armature except Shiuiu 

 as that term is used by me, and here I found it impossible to give it any 

 value, because if I had done so, very divergent species (superficial ap- 

 pearance considered ) would have come into the same genus and closely 

 allied species would be separated ; the modifications are so gradual also 

 that it would be difficult to limit each genus. Very divergent forms 

 superficially and perhaps structurally have thus been run together into 

 one genus, but the differences are so gradual that I could discover no 

 dividing line between the groups safe enough to base a genus on. 



The tarsal claws vary somewhat as will be seen by the few figures 

 given. In the two species of Daxyspoudaea they are very strongly 

 dentate. In Heliolonche they are perfectly simple, and in MeUcliptria 

 obsoletely toothed. 'J here are variations other than those figured, but 



