The Hardtail conger (Gnathophis cinctus, also known as the Catalina conger) is an eel in the family Congridae (conger/garden eels). It was described by Samuel Garman in 1899, originally under the genus Atopichthys. It is a tropical, marine eel which is known from the eastern central and southeastern Pacific Ocean, including Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Peru, and the United States. It dwells at a depth range of 9-336 metres, and leads a benthic lifestyle, burrowing into loose sand. Males can reach a maximum total length of 42 centimetres.