_Butterfly._--The upper side of the wings, depicted in the plate, requires no comment. On the under side the black marginal markings of the primaries reappear as pale-brown markings. The hind wing is pale yellow or grayish-saffron, crossed by an ill-defined pale-brown transverse band of spots, and has the veins marked with pale brown, and interspersed between them pale-brown rays on the interspaces. _Early Stages._--What we know of these is derived principally from Abbot through Boisduval, and there is opportunity here for investigation. The species has a wide range through tropical America, and is not uncommon in the Gulf States. (2) =Pieris beckeri=, Edwards, Plate XXXIV, Fig. 8, ♂; Fig. 9, ♀ (Becker's White). _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. Winter form =vernalis=, Edwards, Plate XXXIV, Fig. 18, ♂. What has been said of the typical or summer form does not hold true of this winter form, which emerges from chrysalids which have withstood the cold from autumn until spring. The butterflies emerging from these are generally dwarfed in size, and in the males have the dark spots on the upper side of the wings almost obsolete or greatly reduced, and the dark markings along the veins on the under side well developed, as in _P. occidentalis_. The females, on the contrary, show little reduction in the size and intensity of any of the spots, but rather a deepening of color, except in occasional instances.