Sea Shell City:
http://www.seashellcity.com/hermitcrabs.html
Naples:
http://www.naplesseashellcompany.com/hermit_crab_shells.html
Wonders of the Sea:
http://www.sealifegifts.net/shells_small.html
The Hermit Crab Patch:
http://www.hermitcrabpatch.com
Sea Shell World
http://www.seashellworld.com/hermit-crab-shells.html
Shell Horizons
http://www.shellhorizons.com/products.asp?category=74
Sea Shell Shop
http://www.seashellshop.com/Replacement-Shells/
Richard’s Sea Shells (Formerly Deltona Shells)
http://www.richardsseashells.com
Searching on Etsy or Ebay will also yield a lot of results for shells.
If you know of another quality web site, please feel free to e-mail us the link so we may add it to our list.