SiphonostomataSi`pho*no*stom"a*ta\, n. pl. [NL. See Siphon, and Stoma.] (Zo["o]l.) (a) A tribe of parasitic copepod Crustacea including a large number of species that are parasites of fishes, as the lerneans. They have a mouth adapted to suck blood. (b) An artificial division of gastropods including those that have siphonostomatous shells.