Looks like you got plenty of slipper shells, and a red-beard sponge. Do keep an eye on these guys long-term. Long Island Sound's waters are significantly chillier than the temperatures your tang and firefish are used to, which may cause some stress for the new critters.
Will follow closely, 'cause this looks both fun and educational!
~Bruce
Thanks!! I will watch closely for sure! Is that what they are called? "Slipper snails?" I plan to feed them to the tank mostly, while they clean the tank. Swap shells out, crush them into small bits, start selling it as calcium reactor media! LOL :-D