Genus Tharyx Webster & Benedict, 1887

Type Species: Tharyx acutus Webster & Benedict, 1887, designated by Hartman, 1959.

Diagnosis (after Blake 1996b). Prostomium conical; peristomium elongate, with pair of grooved dorsal tentacles arising anterior to chaetiger 1; first pair of branchiae frequently on peristomial segment, arising immediately posterior to dorsal tentacles; abdominal segments sometimes beadlike; chaetae including simple capillaries and acicular spines with irregular notched tips, appearing more or less bidentate with a pair of stunted or rounded knobs, but never with distinct, sharply pointed teeth.