priapuloidea

from The Century Dictionary.

• A group of unseg-mented vermiform animals having an anterior and a posterior terminal opening of the alimentary canal, the central nervous system not separated from the ectoderm, and the renal and reproductive organs entirely separate from the body-cavity. They are marine animals found in the sand and mud of the North Sea. The sexes are separate and the development is unknown. It contains the single family Priapulidæ.