Nephasoma Pergament

Diagnosis: Introvert about equal to or shorter than trunk. Hooks, when present, usually scattered. Body wall with continuous muscle layers. Tentacles arranged around the mouth but may be reduced in both size and number. Two introvert retractor muscles, often partially fused. Contractile vessel without villi. Spindle muscle not attached posteriorly. Two nephridia. Species generally small to medium sized (trunk <50 mm long).