Regents of the University of Michigan
Animal Diversity Web: Gastropods
An overview of the many types of gastropods, slugs and snails found around the world. Included is a large bank of photos of the various species and their classification information.
Georgia State University
Georgia State University: Hyper Physics: Mass, Weight, and Weightlessness
Site from HyperPhysics dealing with the topic of mass and weight. In addition the site deals with weightlessness. The numerous links to other pages help the student see how ideas are interrelated.
SRI International
Performance Assessment Links in Science: Stimulus/response in Invertebrates
Students are given some guidelines to develop experiments to see how slugs or earthworms repsond to stimuli such as vinegar and light. This activity is designed to last 4 class periods.