64 GROTE—THE DESCENT OF THE PIERIDS. [Jan. 5, 
EXPLANATION OF PLATE I. 
The figures are obtained by an improved photo-lithographic pro- 
cess. $= subcostal vein; A ==radius 1to 5; J&#=— medias tor. 
¢€= cubitus 1 to 2; 4 =analt to 34 \ Phe costal veims aregab- 
sent in the Lepidoptera through reduction. The fork at base of 
second anal of primaries is not numbered. The first anal is usually 
obsolete. On hind wings h. s. = humeral spur. 
Fig. 1. Azalais gigantea. Typeof genus. This immaculate and more special- 
ized form differs from ZLeptidia by the production of the primary wing between 
Mi and 2. On hind wings the position of J/1 is further removed outwardly 
and 4/2 is nearer 3; the humeral spur is also straight and truncate. 
Fig. 2. Leptidia sinapis. Type of genus and subfamily. This latter is char- 
acterized, as compared with the Dismorphiane, by the retreating discal cells and 
central position of second median on primaries. No trace of fork to second anal. 
Compare with preceding figure. 
Fig. 3. Pseudopierisnehemia Q. Type of genus. An isolated and specialized 
form belonging to the Dismorphianz, which have proportionate discal cells and 
second median vein cubital on both wings. In Pseudopieris the cell retreats in 
its upper part, leaving the first median on primaries free from radius. The first 
radial is free to costa; h.s. Y-shaped. The uniformly pale color here accompa- 
nies a peculiar specialization in the veining. 
Fig. 4. Leptalis astynome 2. Typeof genus. The first radial fuses with sub- 
costal; first median from radius at upper corner of discal cell. On hind wings 
Mr from radius well beyond discal cell. 
Fig. 5. Enantia melite 2. Type of genus. The first radial branch is bent 
and fused with subcostal. 4/1 from cross-vein close to upper corner of discal 
cell, hence more generalized than Leptalis. 
Fig. 6. Acmepteron nemesis S. Type of genus. The proportions of the wings 
are Orthopteralike. The backward spur on discal cell, a relic of the base of 
media, marks the generalization. AI straight, fusing with subcostal. J/1 from 
¢cross-vein, further removed from upper corner of cell thanin Zxan¢ia, hence the 
more generalized form. Hind wings with discal cross-vein joining 4/1 at furca- 
tion with radius. This dark form has ancestral characters compared with the 
two preceding. The Leptidianze belong to the fauna of the Old, the Dismor- 
phiane to that of the New World, 
