Eukaryota  >  Metazoa  >  Hemichordata

Family	Genus	Species
Cephalodiscidae	1	6
Harrimaniidae	6	34
Ptychoderidae	3	21
Rhabdopleuridae	1	12
Saxipendiidae	1	2
Spengelidae	2	8
Torquaratoridae	4	28