<marine biology> Destitute of a siphon or breathing tube; said of many bivalve shells. ... An asiphonate mollusk. ... (19 Mar 1998) ... Found on http://www.encyclo.co.uk/local/20973
A·si'phon·ate adjective (Zoology) Destitute of a siphon or breathing tube; -- said of many bivalve shells. -- noun An asiphonate mollusk. Found on http://www.encyclo.co.uk/webster/A/129