by William Swainson

“ The palpi in this insect will be found at variance with the generic character now given; a striking proof that in a natural system no single part can be taken as an unerring criterion for generic distinction, without making it eventually an artificial one. The Colias Drya of Fabricius has the same formation of palpi, but is a totally different insect. ”

“ Antennæ short, cylindric, gradually thickening to their tip, which is naked and abruptly truncate. Anterior wings trigonal. Abdomen of the male with the last joint pointed, and a slender incurved hook beneath ”