Sentence Examples


  • An apparent, but not real, exception is Halecium halecinum, in which the blastostyle is produced from the side of a nutritive polyp, and both are enclosed in a common theca without a partition between them (Allman [1] p. 50, fig.
  • A-D are stages common to both; from D arises the hydrotheca (E) or the gonotheca (F); th, theca; st, stomach; 1, tentacles; m, mouth; mb, medusa-buds.
  • In B the spadix of the upper bud has protruded itself through the top of the gonoat the base of the theca and the acrocyst (ac) is secreted round it.
  • - Corallum of Caryophyllia; semi-diagrammatic. th, Theca; c, costae; sp, septa; p, palus; col, columella.
  • (3) The theca or wall, which in many corals is not an independent structure, but is formed by the conjoined thickened peripheral ends of the septa.