phacellus

plural phacelli

1. biologyOne of the filaments on the inner surface of the gastric cavity of certain jellyfishes.

   ... the phacellus placed on it, which is formed by a bow-shaped series of gastral filaments.

   1965, William Alexander Forbes, Report on the Anatomy of the Petrels (Tubinares), Collected During the Voyage of H.M.S. Challenger, in the Years 1873-1876

   2 more examples

   Closer inspection, however, shows that the two phacelli of each pair originate as diverging limbs, from a simple interradial phacellus deep in the bottom of the basal stomach.

   1882, Great Britain - Challenger Office, Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76 Under the Command of Captain George S. Nares ... and the Late Captain Frank Tourle Thomson, R.N., page 78

   [...] phacelli are well developed, occupying the interradial sides of the octagonal stomach cavity. Each phacellus consists of from eight to twelve brush-like filaments.

   1909, The Journal of the College of Science, Imperial University ..., page 6