26 
The Potherb P>utterfly. Pieris oleracea. Boisd. 
This species is easily distinguished from the others here mentioned, 
the butterfly being entirely white or yellowish white, without, spots; 
the wings are, as in the others, somewhat dusky at the base but there 
are no black spots on either the anterior or posterior wings; they are 
more or less tinted with yellowish or straw color, especially on the 
underside. 
The caterpillar is of a dark, velvety green color, somewhat uniform 
in size throughout its length, without any distinct stripes; segments 
not very distinctly marked; length when fully grown one inch and a 
quarter to one inch and a half. 
The chrysalis is pale green or white, finely dotted with black; the 
anterior point is generally rather more prolonged than in either of the 
other species. 
This species is found only in northern latitudes, its range in this 
State not extending even to the central portion, so far as I am aware. 
North American Sfecies of Pieris. 
I have concluded to give here, for the benefit of the readers of this 
report, a short account of the North American species of this genus, 
w r ith some remarks in reference to the habits and geographical distri¬ 
bution of the species. 
As has been truly remarked by Rev. J. G. Wood (Insects at Home), 
common as these butterflies are, they have raised quite a controversy 
among entomologists, and have been shifted backward and forward 
until it is scarcely possible to reconcile the conflicting views. I shall 
therefore treat the genus as employed by Boisduval and as Dr. Morris 
defines it in his synopsis, with such restrictions as appear to be re¬ 
quired by the most recent authorities. 
In this sense it may be distinguished from the closely allied genera 
by the antennae not being truncated and having the club ovoid and 
compressed; the palpi less compressed, with the last joint always near¬ 
ly as long as the preceding; by the less robust body, and the thinner 
wings, which, at least so far as our species are concerned, have the 
ground color white or at most with but a faint tinge of yellow, and 
often more or less spotted with black. 
They never have those central silvery or ferruginous spots which 
are always present on the underside of the wings of the Colias or 
sulphur butterflies. 
In order to illustrate the difficulty economic etomologists’ experience 
in attempting to present to non-scientific readers, in a work of this 
