Korotkevitschia Friedrich 1968

Genus: Korotkevitschia Friedrich, 1968

Generic diagnosis: Pelagic hoplonemerteans with modified monostiliferous proboscis armature; bulb region and bulb duct not developed; basis, central stylet and diaphragm absent; two accessory stylet pouches with posterior opening; rhynchocoel reaches posterior end of body; rhynchocoel wall with interwoven musculature; mouth and rhynchodaeum open separately; precerebral septum closed; body wall with non­fasciated diagonal muscles; longitudinal musculature not anteriorly divided, with honeycomb fascial substructure; dorso­ventral musculature weakly developed; longitudinal stomach musculature present; frontal organ present; eyes absent; frontal, cephalic and submuscular glands present in precerebral region; cerebral organs lie beside brain and reach behind dorsal ganglia, cerebral organ canals branched, with two distinct kinds of epithelium; cerebral organ furrows lack secondary grooves; cerebral ganglia with neither neurochord cells nor inner neurilemma; lateral nerve cords without accessory nerve, with a thin band of connective tissue with numerous myofibrils; foregut divisible into stomach and pyloric region; intestinal caecum with lateral pouches only; lateral intestinal pouches large and lobed; very long rectum with well­developed sphincter of circular muscle fibres; blood system simple, without pseudometameric transverse connectives; mid­dorsal vessel with single vascular plug; excretory system well developed, opening to exterior in midbody region; testes lie in posterior quarter of the intestinal region, gonadal muscle meshwork not developed.

Type species: Cratenemertes pelagicus Korotkevitsch, 1961.