1900. } GROTE—THE DESCENT OF THE PIERIDS. 29 
Pieris and Ascia, which agree, hence a little more generalized. 
Mi ascends radius; J/2 in stage of Ascia. ‘Trace of fork at base 
of second anal. Hind wings with humeral vein as in Ascza, 
pointed, turning sharply toward apex of wing. 
There is probably a direct descent between AZplofhris and the 
much more generalized (Vepheronia. I interpolate, however, here 
the intermediate genus Ava, which, more generalized than AZyloth- 
vis, probably connects with the Ascza line. 
Gen. Ava de Nicé€ville, 1898. 
Type: A. affinis (Voll.). 
Ava affinis. 
Wings ample, entire; radius four-branched; Ar and 2 in 
the Pierid position above cell; #3 a rather long fork out of R4 
+ 5. Cell closed; M1 ascends radius, perhaps for a little 
shorter distance than in Ascza, than which it would be thus more 
generalized ; JZ2 is also a little further from radius than in Ascza 
and the cross-vein between them is concave or depressed, not 
straightly oblique. Trace of fork to second anal at base. Hind 
wings with humeral spur pointed, turning sharply toward apex of 
wing. 
This genus is of the Asczéa type, not of Prevzs. As it is a little 
more generalized than AZy/othris, I bring it in here. This is to be 
seen by the longer apical fork of #3; by the shorter stem of J/1 ; 
the cross-vein between 4/2 is roundedly concave or depressed, 
not angulate as in AMZj/othris, and the second median standing a 
little further off from radius. 
Gen. Wepheronia Butler, 1870. 
Type: N. poppea (idotea). 
Nepheronia poppea. 
Wings ample ; external margin a little retreating below apices ; 
color and pattern of AZplothris. Radius five-branched, generalized, 
approaching the generalized form of the Anthocharid line; AI 
and #2 in original position above cell; #3 and #4 near apices 
out of #5, comparatively short furcations. Cell closed; J 
does not ascend radius, but arises out of cross-vein just before 
radius ; cross-vein angulate between 4/1 and J/2, a little degener- 
ate between J/2 and 473. Hind wings with humeral spur curving 
gently. toward apex of wing. 
