Although we do not dissect any critters in Environmental Science, I know for sure you clicked on this link because you were curious.... check it out!!! :)
Some interesting information on dissections:
*Earthworms
*Grasshoppers
*Crayfish
*Frogs!
Earthworms
http://biog-101-104.bio.cornell.edu/BIOG101_104/tutorials/animals/earthworm.html
http://en.wikipedia.org/wiki/Earthworm
Grasshoppers
http://en.wikipedia.org/wiki/Grasshopper
http://www.enchantedlearning.com/subjects/insects/orthoptera/Cricket.shtml
Crayfish
http://en.wikipedia.org/wiki/Crayfish
http://www.mackers.com/crayfish/info.htm
http://www.enchantedlearning.com/subjects/invertebrates/crustacean/Crayfishprintout.shtml
Bullfrog
http://animaldiversity.ummz.umich.edu/site/accounts/information/Rana_catesbeiana.html
http://en.wikipedia.org/wiki/Bullfrog
http://allaboutfrogs.org/info/species/bullfrog.html