My general impression is that a Devonian age might be indicated. The collection contains:

1) large modiomorphids, some of which have an umbonal keel like Goniophora; however, the keeling may be preservational and not original. Large Goniophoras are most common in Devonian rocks, but the total range of this genus is Ordovician-Lower Permian. The non-keeled modiomorphids have a shape similar to the Ordovician genus Modiolopsis and the Devonian genus Modiomorpha. These genera differ in dentition, a feature not preserved on these specimens. 2.) An indeterminate myophorid, and 3) large probable pholadomyaceans which are wide like post-Ordovician forms.

This combination of shapes suggests a possible Devonian age, although additional material could readily change this pick, or reenforce it.

The rock does contain carbonate and could be prepared for conodonts.