This one is bugging me!!!!
I know this is a brachiopod. I found it at the Reedy Point spoils along the C and D Canal in Delaware. It is 1cm in diameter.
I have found two of them in the sand but none of them in the books. I have looked in Weller 1907, Wade 1926, Stephenson 1923, Richards 1958 and 64, and Lauginger 1988. I asked the folks at the repository for the Monmouth Amateur Paleontological Society. No dice. Look familiar to anyone?