Environmental Sciences
Biodiversity
Algaebase
An algea database that includes information on marine, freshwater and terrrestrial organisms. An aid to taxanomic studies.
Biodiversity Hotspots
Information on the most threatened and fertile reservoirs of plant and animal life in the world.
URL: http://www.biodiversityhotspots.org/xp/Hotspots/Pages/default.aspx
Animal Diversity Web
An "online database of animal natural history, distribution, classification, and conservation biology at the University of Michigan."