My guinea pigs identity crisis

Question
I've been trying to research the breeds of my two guinea pigs.  One is the American breed, but the other one looks much more like a hamster; his eyes are much bigger and his head is shaped more like a hamster's than a guinea pig's.  He isn't growing much at all in respect to his cavy counterpart, either, and he bites -- A LOT.  I've read so many sources that say cavies don't bite much while hamsters do.  Perhaps I'm looking in the wrong places, or maybe I'm just daft, but is it possible that Rugburn (this troublesome pig) is a crossbreed?  It would sure explain his antisocial behavior.

Thanks!

Answer
Diana,
You may be right, I have never heard of crossbreeds like this, but it sure does sound like it!
I am afraid there is nothing you can do!  If your still able to take him back to the pet shop it may be for the best, some crossbreeds don't live for long or live healthily!
Or you may be 'daft' I am not sure without seeing him myself!
try this:
http://z.about.com/d/exoticpets/1/0/E/k/PikaMainpic1.JPG

This is a supposed crossbred, so if yours looks like this you may be right!

ALSO!
thankyou as one of mine looks a lot like that picture i sent you, just all cream! !! !
how odd!!
Megan