Echiuroidea
plural noun
Ech·i·u·roi·dea
ˌekēyəˈrȯidēə
: a group of marine worms of obscure position though commonly classed as a division of Gephyrea and distinguished by a sensitive but nonretractile proboscis overlying the mouth which in some forms (as some worms of the genus Bonellia) may attain great size
Word History
Etymology
New Latin, from Echiurus + -oidea