echiuridæ

from The Century Dictionary.

• The leading family of Echiuroidea or chætiferous gephyreans, having the oral end of the body produced into a grooved proboscis, containing the long esophageal commissures which meet in front without ganglionic enlargement, and having on the ventral side two hooked setæ anteriorly, with sometimes circles of setæ posteriorly, the mouth below the proboscis at its base, and the anus terminal.