_Butterfly._--Similar to the preceding species, but smaller, the white more lustrous on the under side, and the green markings on the under side of the wings heavier. Expanse, 1.20-1.40 inch. _Early Stages._--We know very little of these. The species is reported from California, Colorado, and Alberta. I possess a singular varietal form or aberration from Arizona, in which the black spot on the upper side of the primaries fills the outer half of the cell. (4) =Euchloë rosa=, Edwards, Plate XXXII, Fig. 39, ♂, _under side_ (Rosa). _Butterfly._--Pure white, without any red at the tip of the primaries. The transapical black band is broken in the middle, and a black bar closes the cell. The under side is well represented in the plate. Expanse, 1.35-1.40 inch. _Early Stages._--Entirely unknown. The species is found in Texas. (5) =Euchloë cethura=, Felder, Plate XXXII, Fig. 26, ♂; Fig. 27, ♀; form =morrisoni=, Edwards, Plate XXXIV, Fig. 1, ♂ (Cethura). _Butterfly._--This delicate little insect, for the identification of which the plates will abundantly serve, has been regarded as existing in two varietal forms, one of which has been named after the indefatigable collector Morrison, whose death is still lamented by the elder generation of American entomologists. The varietal form is characterized by the heavier green markings of the under side of the wings. Expanse, 1.25-1.40 inch. (6) =Euchloë pima=, Edwards, Plate XXXII, Fig. 33, ♂ (The Pima Orange-tip). _Butterfly._--This beautiful and well-marked species, the most brilliant of the genus, is yellow on the upper side in both sexes. The red of the upper side appears on the lower side. The hind wings are heavily marked with solid green bands. Expanse, 1.50 inch. _Early Stages._--Unknown. The only specimens thus far known have come from Arizona. (7) =Euchloë genutia=, Fabricius, Plate XXXII, Fig. 37, ♂; Fig. 38, ♀; Plate II, Fig. 5, _larva_; Plate V, Fig. 59, _chrysalis_; Fig. 6, p. 4, _egg_ (The Falcate Orange-tip). _Butterfly._--This species is readily recognized by the decidedly falcate tip of the fore wings. The first brood appears in early spring. It is single-brooded in the Northern States, but is double-brooded in the western portions of North Carolina, where I have taken it quite abundantly late in the autumn. Expanse, 1.30-1.50 inch. _Early Stages._--The life-history is well known. The caterpillar feeds on _Sisymbrium_, _Arabis_, _Cardamine_, and other cruciferous plants. It ranges from New England to Texas, but is not found, so far as is known, in the regions of the Rocky Mountains and on the Pacific coast. (8) =Euchloë lanceolata=, Boisduval, Plate XXXII, Fig. 30, ♂ (Boisduval's Marble).