Cirrus (biology)

: cirri, /ˈsɪraɪ/ SIRR-eye, from the Latin cirrus meaning a curl-like tuft or fringe) is a long, thin structure in an animal similar to a tentacle but generally lacking the tentacle's strength, flexibility, thickness, and sensitivity.

431 Among the bristleworms, a cirrus is a tentacular growth near the head or notopodium containing sense organs and may be either dorsal, ventral, or lamellar.

[2] Among the ribbonworms, the caudal cirrus is a small thread-like growth at the posterior end of the worm.

[3] Among feather stars or barnacles, a cirrus is a long slender gripping or feeding appendage.

[4] In sea lilies, the cirri are the thin strands that line the animal's stalk.