Poem help.

I'm interested to know exactly what this means...
А прозрачные ветрильцы
Будто бабочкины крильцы.

From what I gather, And transparent <something> as if butterfly wings
Butterfly wings... is that right?

Also, what is ветрильцы, some sort of sails perhaps?

I did a google search on both these words
ветрильцы
крильцы
and got 35 hits on each of them.

All the hits refer directly to the poem by Pushkin.
He must have made up those words himself. :D

I would guess that "ветрильцы" = "winds".

Ветрильцы -маленькие ветрила - маленькие паруса.
Крыльцы - маленькие крылья