The Madison Cave isopod, Antrolana lira, is a freshwater, cave-dwelling crustacean species. It is in the family Cirolanidae and it is the only species of its genus Antrolana. This isopod can be found in flooded limestone caves and karst aquifers throughout the Great Appalachian Valley of Virginia and West Virginia. The Madison Cave isopod has been listed as a vulnerable species on the IUCN Red List since 1983 and as a threatened species under the United States Endangered Species Act since 1982. The species was named after the cave in which it was first discovered, Madison Saltpetre Cave. Very little is known about the life history and behavior of the Madison Cave isopod.