Diplocardia
Diplocardia is a genus of North American earthworms with 52-57 known species that is remarkably similar to Australian Diplotrema Spencer, 1900.
Species include Diplocardia pettiboneae and Diplocardia longa, with bioluminescent mucus.
The second largest earthworm in North America is ''Diplocardia meansi and is endemic to Rich Mountain in the Ouachita Mountains.