Trunk compact, orally flattened (Appendicularinae-trunk). Spiracles small and circular. Hood lacking. Mouth without lips or lobes. Endostyle short, nearly straight. Esophagus curved, entering the stomach from the left. Alimentary tract arranged upon or to the right of rectum. Gonads adjoining the alimentary tract postero-dorsally. Tail fin tapering toward the root for some length, deep notch at its distal end (Appendicularinae).
A single species recorded from the South Atlantic Ocean.
Appendicularia sicula Fol, 1874