FIGURE 17. Thecate hydroids. a in Additions to the hydroids (Cnidaria, Hydrozoa) of the Bay of Fundy, northeastern North America, with a checklist of species reported from the region

FIGURE 17. Thecate hydroids. a, Tiaropsis multicirrata, stolon and pedicellate hydrotheca, ROMIZ B3089. Scale equals 0.1 mm. b, Tiaropsis multicirrata, stolon and pedicellate hydrotheca, ROMIZ B3089. Scale equals 0.1 mm. c, Obelia bidentata, part of colony, with three hydrothecae, ROMIZ B3121. Scale equals 0.25 mm. d, Obelia bidentata, hydrotheca and hydranth, ROMIZ B3121. Scale equals 0.1 mm. e, Halecium marsupiale, part of hydrocaulus with hydrophores and three hydrothecae, ROMIZ B4132. Scale equals 0.2 mm. f, Halecium marsupiale, hydrophore and hydrotheca with one renovation, ROMIZ B4132. Scale equals 0.1 mm.