Source : Webster's Revised Unabridged Dictionary (1913)

Sipunculacea \Si*pun`cu*la"ce*a\, n. pl. [NL., from Sipunculus,
   the typical genus. See {Siphuncle}.] (Zo["o]l.)
   A suborder of Gephyrea, including those which have the body
   unarmed and the intestine opening anteriorly.