Vibraculum \Vi*brac"u*lum\, n.; pl. {Vibracula}. [NL., dim. from
L. vibrare to vibrate.] (Zool.)
One of the movable, slender, spinelike organs or parts with
which certain bryozoans are furnished. They are regarded as
specially modified zooids, of nearly the same nature as
Avicularia.
[1913 Webster]