INVERTEBRATE and micro-fossil collections vary in size, scope, degree of documentation, quality of curation, purpose, usage, and security. This chapter introduces the main categories of fossil collections and curatorial attention, and documents the sources and uses of invertebrate paleontological materials. The term ‘permanent collection’ is used to describe collections housed in professional collections-care institutions that provide long-term commitment to collection security and curation. Invertebrate fossils include the hardparts (spicules, shells, etc., other body fossils [e.g., impressions, casts, and molds]), tracks, trails, and burrows attributed to invertebrates, and organic molecules. Microfossils, included here for convenience only, include the same kinds of remains of prokaryotes, protists, and tiny invertebrates. This book is the product of an National Science Foundation funded workshop organized to address specific concerns about curatorial practices in invertebrate paleontology. For this reason the focus of this chapter is on invertebrate fossils. Nevertheless, the concepts and uses of collections described below apply directly to paleobotanic specimens, and to most vertebrate fossils.