& THE ENTOMOLOGIST. 



Mexico,' in which he very correctly stated that " the venation is 

 subject to variation"; nevertheless he took the trouble to give 

 the following nerve-characters for the groups : — 



Euchloe, Hiibner (=Anthocharis, Schatz). — Fore wings with 

 12 veins ; veins 6-9 on a short stalk, sometimes with vein 6 free. 



Anthocharis, Boisd. (= Phyllocharis, Schatz). — Fore wings 

 with 12 veins; veins 6-9 on a long stalk, sometimes with vein 10 

 also on a stalk. 



^Midea (Herrich-Schaffer, not Schatz). — Fore wings with 11 

 veins ; veins 6-8 on a stalk ; vein 9 absent. 



Now if these characters were constant, there would be no 

 reason whatever why the three named groups should not stand 

 as distinct genera ; but unhappily they are by no means con- 

 stant, as I shall now proceed to show. 



In the wet season form of E. sara (the typical form) there 

 are almost invariably 12 veins in the primaries, but we have one 

 example in which vein 8 is absent. In our examples of the dry 

 phase there are 12 veins, but we have three examples of an 

 insect which might easily be recognized for the same thing from 

 Vancouver, all of which have apparently lost vein 9. Our 

 examples of what I believe to be E. thoosa and stella all have 

 12 veins, but five examples of E. julia from south-west Colorado 

 and Arizona have apparently lost vein 9. 



It would have seemed advisable to distinguish the Vancouver 

 representative of E. reakirti by a separate name; only (unluckily 

 for the species-maker) we possess a fourth example from the 

 same collection in which 12 veins are present, but which, never- 

 theless, varies in another respect, vein 5 being emitted from 6, 

 instead of from the cell. 



Dr. Beutenmiiller includes E. cethura and E. pima with E. 

 genutia under Midea on the ground that they have only 11 veins 

 to the primaries ; but he seems to overlook a more important 

 character which proves their close relationship to Zegris, viz. 

 their extremely short antennae. If Zegris is sufficiently distinct 

 from this extremely variable genus to stand apart, in my opinion 

 it has a greater claim upon E. cethura and E.pima than Euchloe 

 has, in spite of the absence of that very uncertain little "vein 9." 



Anthocharis of Beutenmiiller = Phyllocharis, Schatz, is de- 

 scribed by the later author as having 12 veins, veins 6-9 on a 

 long stalk ; but neither of these characters is constant, for 

 whereas E. hyantis has an extremely short furcation of vein 7 

 (and consequently possesses 12 veins), the nearly related E.venosa, 

 from Thibet, and E. daphalis, from north-west India, have only 

 11 veins, vein 9 being apparently absent. 



Is vein 9 ever absent ? In my opinion it is present throughout 

 the genus ; but veins 7 and 8, which are extremely variable in 

 relation to the length of their furcation, are sometimes completely 

 fused, or (as Sir George Hampson expresses it) coincident. 



