Thanks for the comments everyone

. You are soo lucky that you can collect cephalopods yourself - I would love to go fossil hunting in England some day. I have only found fossil whale bone (just a bit...) bivalves and gastropods in California. My 9 year old daughter found a Rugosa (horn coral) in our backyard last year.

It was in a pile of gravel so I don't think it originated in my backyard.
I used to teach a fossil class to elementary school students and I often used the Nautiloid fossil to compare to a Nautilus shell that was cut in half.
I found the Scaphites at a local antique fair. There is a man who just sells little fossils that he has collected. I didn't notice that it was a heteromorph until I got home and part of the matrix popped off, revealing the inner whorls of the shell. I don't think he realized either, because I think I talked him down to $1.00.
This last fossil is an endoceras that I purchased on ebay for $2 - I have posted on Tonmo previously, but I just included it here, since it rounds out my current collection.