Tubificoides blakei and T. methanicus, both new species of oligochaetes, are described from 2156 and 2170 m depth on the Blake Ridge Diapir, near the intersection of the Carolina Rise and the Blake Ridge, off the continental shelf of North and South Carolina (U.S.A. East Coast). Tubificoides blakei is characterized by the long, parallel teeth of its bifid crotchets, and its mushroom-shaped, cuticular penis sheaths. It appears most closely related to two other deep-water species reported from the northwest Atlantic Ocean, T. bruneli Erséus, 1989 and T. aculeatus (Cook, 1969) but differs from these in the detailed morphology of the penis sheaths. Tubificoides methanicus lacks hair chaetae but is recognized by its numerous bifid chaetae, which have long, somewhat diverging teeth, the upper teeth often being longer than the lower ones, and its smooth, funnel-shaped penis sheaths. It does not seem to be closely related to any other known deep-sea species of Tubificoides, but it resembles the littoral, holarctic, T. pseudogaster (Dahl, 1960), differing from the latter mainly by its greater number and larger size of the posterior chaetae.