Camarotoechia is a small brachiopod that is fairly common in the Paleozoic. At times it seems to be another "dumping ground" for similar looking shells like Spirifer is. I believe that the fossil shown below is Camarotoechia and was found in the Keyser formation in Pennsylvania.
I've posted pictures of Camarotoechia from other localities like Arkona, Oklahoma and New York.
The Keyser formation is Silurian to Devonian in age (Pridoli to Lockhovian stage).