Echiuroidea n. pl. : A division of Annelida which includes the genus Echiurus and allies. They are often classed among the Gephyrea, and called the armed Gephyreans.

Example:


Taxonomy
proboscis, body, ventral, vessel, Echiuroidea, mouth, Bonellia viridis, ciliated, four species, organ, skin, vesicles, intestine, dorsal vessel, Echiurus, larva, layer, nephridia.

Defination from the web:
Echiuroidea. From LoveToKnow 1911. ECHIUROIDEA (Gr. ... The Echiuroidea consists of the following genera: - (r) Bonellia (Rol.), with four species, widely distributed, but inhabiting the temperate and ...