Phylum Mollusca - Mollusks - includes snails, slugs, clams, scallops ...

Class Hirudinea - LeechesMost are freshwater, some terrestrial and marine - mostare predators or scavengers, some are parasitesLoss of septa between segments, most have no setaeHave suckers at both ends for prey capture, attachment,and locomotionHermaphroditic with mating similar to earthwormsleeches appear to have evolved from earthwormsExample: Hirudo medicinalisthe medicinal leech - aparasite - mouth haschitinous teeth, attaches,bites, secretes anticoagulant“hirudin” -leeches are used to removeblood from beneath skin aftersurgery and from some woundsHirudin is used to prevent clotformation during surgery