The invertebrate fossil collection of the Museum of Comparative Zoology, Harvard University, was begun by Louis Agassiz in the mid-1800s. It has grown to be an internationally important collection of type and reference specimens of all geologic ages from around the world. Curatorial improvement of this collection will provide researchers with greater access to specimens of interest, and will promote new research by uncovering and documenting type specimens that are now filed with non-types. A catalogue of type cephalopods has been completed recently, and work on a type trilobite catalog is now being initiated. Natural history collections are the libraries in which the history of life are preserved. This collection has served generations of students and researchers in their explorations of the evolutionary past. Curatorial efforts such as this will ensure that future generations of paleontologists, invertebrate zoologists, and evolutionary biologists will continue to have access to this critically important resource.