You are right, Deal, the walleye is the largest member of the perch family. Sauger are also members of the perch family.
http://www.dnr.state.mn.us/fish/walleye/biology.html
There are also saugeye
http://www.dnr.state.oh.us/Home/species_a_to_z/SpeciesGuideIndex/saugeye/tabid/6750/Default.aspx