26 
PIEIUD.E. 
Fam. 2.— PIERID^. 
Larva. — Smooth or downy, more or less tapering towards the 
extremities, not furnished anteriorly with a retractile fork. 
Pupa. — x^ngular, slightly compressed laterally, and tapering 
to a point, attached by the tail, and by a transverse median belt. 
Imago. — Head moderately small ; palpi distinct, longer than 
in the last family; antenn^e long and distinctly clubbed. Six 
perfect legs in both sexes. Wings more or less rounded, the hind 
wings neither concave nor dentated. The abdomen received into a 
groove formed by the hind wings. Among the European species 
the ground colour of the wings is white or yellow, but amongst the 
Exotic forms there is great variety of colour. Some species of 
the South-American genus Leptalis exhibit well-marked examples 
of mimicry, their resemblance to certain Heliconidce being very 
striking. 
There seems to be a tendency in the family towards gregarious 
habits. We meet with it sometimes in the larval state, as in the 
case of A-poria Cratcegi, where the caterpillar lives in company 
beneath a web spread over the hawthorn bushes. The Tropical 
genus Callidryas affords examples of this in the perfect state, many 
of the species occurring in swarms or flights of considerable 
numbers, especially on the sea-coasts ; hence probably for purposes 
of migration. Our British species of Pieris, P. Rapce, Napi and 
Brasskw, have been observed both on land and at sea in similar 
migratory swarms. 
Seven European genera are contained in this family — Apoeia, 
PiEEis, Euchloe, Zegkis, Leucophasia, Colias, and Gonepteryx. 
Genus 1. — APORIA, Hub. 
Pieris, Schrank. 
PoNTiA, Fab. 
Antennae long and tolerably thick. Wings semitransparent, 
uniform white. Fore wings without dusky tips, the nervures very 
distinct and black. Hind wings rounded, and white beneath. 
