Type material for 378 nominal species of protists are in the Invertebrate Paleontology Collections of Yale University's Peabody Museum of Natural History. Primary types for 186 nominal species include 112 holotypes, 1,057 syntypes (representing 70 nominal species) and 27 lectotypes. Secondary types for 126 nominal species include 537 paratypes (representing 40 nominal species) and 736 paralectotypes (representing 86 nominal species). Tertiary types of 269 nominal species include 1,785 hypotypes. Most types are from Arizona, Bolivia, Coahuila (Mexico), Kansas, Nebraska, New Mexico, Oklahoma, and Texas, and have been described by C.O. Dunbar, C. A. Ross, F.F. Sabins, J.W. Skinner, M.L. Thompson and T.E. Williams.