Inarticulate brachiopods have no teeth or sockets but rely on muscles to hold their valves together. Inarticulates are generally smaller than the articulates. Concentric growth lines and ribs are common (Thompson 1997).
Here are two examples of Lingula specimens from the Ottawa Area documented by A. E. Wilson in 1956.
1-Lingula cobourgensis
2-Lingula briseis
