Notomyxine is a monospecific genus of hagfish that occurs in the Atlantic Ocean off the southern coasts of South America.

It can be found in the temperate waters of the Southeast Pacific and Southwest Atlantic, as well as the southern coasts of South America.

Notomyxine tridentiger has been found only along the Argentinean continental shelf and southern Chile and has not been reported since 1968.

More research is needed to understand the distribution, population status, habitat, biology, ecology, and impact of potential major threats to this species.

It is found on muddy bottoms of the continental shelf at depths from 6–143 m. The copulatory organ is absent in this species.