The lichen herbarium of the Academy of Natural Sciences of Philadelphia (PH) is among the oldest in North America. At the center of the collection are the herbaria of the early nineteenth century botanists L.D. von Schweinitz and G.H.E. Muhlenberg and the late nineteenth century lichenologist J.W. Eckfeldt. A catalogue of types has not previously been compiled and a search of the lichen herbarium in preparation for this paper yielded a large number of previously unrecognized types (> 150). At this time, the type collection of lichens at PH contains type material of 258 nominal taxa described by the following authors: E. Acharius, T. Ahti, F. Arnold, O.G. Blomberg, I.M. Brodo, O.V. Derbishire, M.J. Dibben, W.L. Dix, J.W. Eckfeldt, C.F.E. Erichsen, B.E. Fink, E.M. Fries, T.M. Fries, V. Gyelnik, M.E. Hale, A. Halsey, H.E. Hasse, J. Hedrick, A. Hue, J. Hulting, A.H. Magnusson, J. Müller Argoviensis, T. Nuttall, W. Nylander, L.D. von Schweinitz, M. Servit, J. Steiner, E. Stizenberger, E. Tuckerman, E.A. Wainio, C.M. Wetmore, H. Willey, and A. Zahlbruckner.