the world > animals > invertebrates > protozoa > class Infusoria > subclass Ciliata > [noun] > order Peritrichida > family Vorticellidae > member of > contractile fibre
stem-muscle1870
1870 H. A. NicholsonMan. Zool. I. 61 A spiral contractile fibre [in Vorticella], which is sometimes called the ‘stem-muscle’.