from
The Collaborative International Dictionary of English v.0.48
Serpula \Ser"pu*la\, n.; pl. {Serpulae}, E. {Serpulas}. [L., a
little snake. See {Serpent}.] (Zool.)
Any one of numerous species of tubicolous annelids of the
genus {Serpula} and allied genera of the family {Serpulidae}.
They secrete a calcareous tube, which is usually irregularly
contorted, but is sometimes spirally coiled. The worm has a
wreath of plumelike and often bright-colored gills around its
head, and usually an operculum to close the aperture of its
tube when it retracts.
[1913 Webster] Serpulian