Hedingia

Deichmann, 1938

5 species

Caudinid with 15 tentacles with 2 pairs of digits but no unpaired terminal digit. No pseudomesenteries attached to the sides of the third loop of the intestine. Spicules huge tables or plates with large perforations and smooth or spinous surface. Exclusively deep water forms. (Deichmann, 1938)

Calcareous deposits large tables (0.15-0.27 mm diameter) with numerous holes in disc; a 3 pillared spire may be present, reduced, or lacking altogether; deposits often spinous. (Pawson, 1970)

Tentacles with two pairs of digits. Deposits large tables (0.15-0.27 mm across) with large perforations, smooth or spinous surface, and high spire of three rods or plates with large perforations and smooth or spinous surface. (Pawson, 1977)