Copyright infringement question

[Carol]

-Tonks:
> Hooch and Pince are not trademarked by WB, because someone else
already had them. Ron Weasley, Hermione, Hermione Granger and Harry
Potter are, of course. You can find trademarks here:
> 
> http://www.uspto.gov/#
> 

Carol responds:
I must be dense or something. (Yes, guys, I see you nodding behind
your hands. ;-) )I found JKR's copyrighted titles on that site, but
not her trademarked characters. Can you give me a more specific link
and/or directions?

Thanks,
Carol