ID Needed

[burro at panama.gulf.net]

I think I might have found a hybrid - 

A butterfly flew across our windshield, and we went back to find it.
(I rescued one the other day.)   I thought it was an Eastern Black
Swallowtail - but the back of the wings do not have any eye, or other
colors other than black and yellow.  The tails are long.  The body was
striped black and yellow - no dots.  Underwings look like EBS.

Any ideas?  Thought it my be a hybrid w/Western Black Swallowtail.

Many thanks.

Incidentally, the drought is over, flowers are delayed, but I think we
will have some fritillaries.  No sulfurs AT ALL.

May