This butterfly is allied to the Cheiranthi, but is a distinct variety,
only recently met with in this island. Mr. Butler, of the British
Museum, has named and fully described this insect, which has hitherto
only been found in Madeira, but is now for the first time enumerated
in the list of Teneriffe Lepidoptera. It is somewhat smaller than the
Cheiranthi, measuring not more than two and a half inches in expanse.
The reverses of the female (which is illustrated) and of the male are
of a grey tinge, in place of the rather bright yellow shade of the
Cheiranthi, sprinkled over with fine black dots. The apical patch is
also grey, and both sexes have long black spots on the fore-wings. The
upper surface is cream-white; the female has two distinctly marked long
black spots on the fore-wings; the male having none. The black apical
markings are similar in both sexes, and a small black spot is seen on
the inner margin of the hind-wing of both male and female.
There are no observations to record on the caterpillar and pupa, as
the specimens of the fly (one of which is illustrated) were netted;
but very possibly larvæ may be found gregariously with the Cheiranthi
in like manner to the Callirrhoe and Atalanta, or the Plexippus and
Chrysippus.
The specimens taken were netted about 500 feet above the sea.