Green-veined White (male)

Great bayucca, the fine details of butterfly identifying. I learn something all the time! I wondered how you saw the diiference... didn't know the trick of clicking on the image to enlarge it. Makes it so much easier to see!

I was wondering too why nobody tried to challenge my ID ;-)...
OK, let's look at both from your link. Just focus on the little triangle on the forewing. In Rapae it is some kind of rectangular or with some kind of a horizontal direction whereas in Napi this patch is really like a triangle and have usually also some very tiny lines which yours has also. Both are the males and I am pretty sure, considering my arguments that it is Pieris napi. Your are invited to take a silent moment and look at the pictures from the link:
Pieris rapae: Take #1 on top or #2 (first in second row):
http://www.ukbutterflies.co.uk/species.p...
Pieris napi: Take #1 on top (click to enlarge):
http://www.ukbutterflies.co.uk/species.p...

wondering bayucca and AnkaMocan, if this might not be the Small white, Pieris rapae.
http://www.ukbutterflies.co.uk/species_f...

The male.