http://www.ext.vt.edu/pubs/fisheries/420-530/420-530.pdf
I found this while researching snails from a trip we made to the Shenandoah River that has turned into a great homeschooling study of aquatic ecosystems.
I found this while researching snails from a trip we made to the Shenandoah River that has turned into a great homeschooling study of aquatic ecosystems.
