Dalejina is a Silurian aged brachiopod that, to me, resembles the genus Rhipidomella that is more commonly found in the Devonian. The specimen below is Dalejina hybrida from the Wenlock formation (Wenlock epoch, Sheinwoodian to Homerian), near Dudley, England. The shell is rounded but slightly oblong with fine raidial ribs on the surface and occasional growth lines. There is a small triangle shaped interarea at the posterior of the pedicle valve as well.
I've found a small shell in the Waldron shale of Indiana that I think is Dalejina and you can see that blog post here.