This laboratory manual supports a one-semester course in invertebrate zoology. Exercises in this manual focus on an approach where you observe specimens, draw them, write down your own observations about them, and then pose questions based on what you observed. This pattern of observing and asking is the same approach zoologists often take when they develop new lines research about what animals do and how their bodies work. The manual includes introductions to microscopy and phylogenetic analysis, and hands-on exercises focusing on representatives from the following animal taxa: Symplasma - syncytial sponges; Cellularia - cellular sponges; Cnidaria - Hydrozoa, Scyphozoa, Cubozoa, and Anthozoa; Platyhelminthes - Turbellaria, Neodermata (Monogenea, Digenea, and Cestoda); Mollusca - Polyplacophora, Gastropoda, Cephalopoda, and Bivalvia; Annelida - Sipuncula, Errantia, Sedentaria; Brachiopoda (articulate and inarticulate); Nematoda; Panarthropoda - Lobopodia, Tardigrada, Arthropoda (Trilobilomorpha, Chelicerata, Arachnida, Crustacea, Myriapoda, Hexapoda); Echinodermata - Asteroidea, Echinoidea, Holothuroidea, echinoderm development; Hemichordata - Enteropneusta; and Chordata - Tunicata, Cephalochordata. I produced these exercises because the prices of textbooks and laboratory manuals have become extremely expensive over the past 20+ years. Students today sometimes have to spend over $90 for a new copy of a laboratory manual in invertebrate zoology. I'm sorry, but in my opinion that's just too much. I field-tested these exercises in my invertebrate zoology course over the past five years, and I just completed a comprehensive review of this material. I hope this lab manual will now help provide at least a little financial relief when it's time for today's invertebrate zoology students to buy books.