Butterfly.—This species, through the green markings of the under side of the hind wings, concentrated in broad blotches on the disk, recalls somewhat the species of the genus Euchloë, and by these markings it may easily be discriminated from all other allied species.
Early Stages.—These have been in part described by Edwards in the second volume of "The Butterflies of North America."
The species ranges from Oregon to central California, and eastward to Colorado.
(3) Pieris occidentalis, Reakirt, Plate XXXIV, Fig. 13, ♂ (The Western White).
Butterfly.—Not unlike the preceding species on the upper side, but easily distinguished by the markings of the under side of the wings, which are not concentrated in blotches, but extend as broad longitudinal rays on either side of the veins from the base to the outer margin.
Early Stages.—These require further investigation. We do not, as yet, know much about them.
The species has a wide range in the mountain States of the West, where it replaces the Eastern P. protodice.
(4) Pieris protodice, Boisduval and Leconte, Plate XXXIV, Fig. 10, ♂; Fig. 11, ♁; Plate II, Fig. 7, larva; Plate V, Figs. 66, 67, chrysalis (see also p. 12, Fig. 26) (The Common White).
Butterfly.—Allied to the foregoing species, especially to P. occidentalis; but it may always be quickly distinguished by the pure, immaculate white color of the hind wings of the male on the under side, and by the fact that in the female the hind wings are more lightly marked along the veins by gray-green.