Spengelidae is a family of worms belonging to the class Enteropneusta, order unknown. The larvae of one of its species, Schizocardium californicum, are known for not expressing Hox genes.

Genera:

  • Glandiceps Spengel, 1891
  • Mazoglossus Bardack, 1997
  • Schizocardium Spengel, 1893
  • Spengelia Willey, 1898
  • Willeyia Punnett, 1903