||Cir"rus (?), n.; pl.
Cirri (#). [L., lock, curl, ringlet.] [Also
written cirrhus.]
1. (Bot.) A tendril or
clasper.
2. (Zoöl.) (a)
A soft tactile appendage of the mantle of many Mollusca, and
of the parapodia of Annelida. Those near the head of annelids are
Tentacular cirri; those of the last segment are caudal
cirri. (b) The jointed, leglike
organs of Cirripedia. See Annelida, and
Polychæta.
&fist; In some of the inferior animals the cirri aid in
locomotion; in others they are used in feeding; in the Annelida
they are mostly organs of touch. Some cirri are branchial
in function.
3. (Zoöl.) The external male
organ of trematodes and some other worms, and of certain
Mollusca.
4. (Meteor.) See under
Cloud.
