neurochord

from The Century Dictionary.

• noun A cord of giant fibers which, in the earthworms and their allies and in some of the thoracostracous Crustacea, accompanies the ventral nervous system, on its dorsal surface. It is commonly regarded as a degenerated nervous structure which has acquired a supporting function, serving a purpose similar to that of the notochord in vertebrates.

from the GNU version of the Collaborative International Dictionary of English.

• adjective (Zoöl.) See neurocord.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Alternative form of neurocord.