Archiannelida \Ar`chi*an*nel"i*da\, n. pl. [NL.; pref. archi- + annelida.]

(Zool.) A group of Annelida remarkable for having no external segments or distinct ventral nerve ganglions. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

Archiannelida

Source: WordNet (r) 2.0
 

Archiannelida \Ar`chi*an*nel"i*da\, n. pl. [NL.; pref. archi- + annelida.]

(Zo["o]l.) A group of Annelida remarkable for having no external segments or distinct ventral nerve ganglions.

Source: Webster's Revised Unabridged Dictionary (1913)