Phascolosomatidea is a subclass of the class
Sipuncula
The Sipuncula or Sipunculida (common names sipunculid worms or peanut worms) is a class containing about 162 species of unsegmented marine annelid worms. The name ''Sipuncula'' is from the genus name ''Sipunculus'', and comes from the Latin ' ...
, the
peanut worms, containing two orders:-
*
Aspidosiphonida containing the single family
Aspidosiphonidae
''Aspidosiphonidae'' is a family of peanut worms. It is the only family in the monotypic order Aspidosiphonida, which is in the class Phascolosomatidea.Gibbs, P.E. (1977): British sipunculans. Academic Press. London. 35p. Ditadi, A.S.F. & Migotto ...
*
Phascolosomatida containing the single family
Phascolosomatidae
Their hooks are arranged in regular rings.
References
Sipunculans
Protostome classes
{{Protostome-stub