Genus Thysanocardia (Fisher)

Remarks. Gibbs et al. (1983) elevated this genus from its former subgeneric status suggested by Fisher (1950). There are only three species ― the type species Thysanocardia procera Möbius, T. catharinae (Grübe) and T. nigra (Ikeda), known for this genus worldwide (Cutler, 1994). The most distinctive morphological character of this genus is the presence of a tentacular crown on the distal tip of the introvert, which requires careful dissection to be seen. Thysanocardia nigra is the sole species occurring in the Pacific, although it has not been previously recorded from Taiwan waters.