These have their summit black, and a minute black point, near the middle.

The under wings are without any spots, but are bordered behind by a cinereous thread.

The underside of the upper wings have the costa and summit covered with spots and minute incontinuous lines of a yellowish colour.

The underside of the lower wings are sulphureous, with very fine undulating or rather incontinuous lines of a yellowish colour.
The species has been named by Captain King, after John Wilson Croker, Esquire, M.P., and first secretary to the Admiralty.
138.

Pieris niseia (n.s.) P.alis albis limbo late nigro; anticis macula media nigra limboque albo-trimaculato; posticis subtus nigro-venosis limbi maculis luteo-notatis.
Obs.