48), where it is ambulatory, in Gonionemus (Trachomedusae), and in Cunina (Narcomedusae), where it is parasitic.
In Gonionemus the actinula becomes fixed and polyp-like, and reproduces by budding, so that here also an alternation of generations may occur.
In the Leptolinae we must first substitute polyp for actinula, and then a condition is found which can be compared to the case of Cunina parasitica or Gonionemus, if we suppose that neither the parent-actinula (i.e.
In Gonionemus the actinula becomes attached and polyp-like and reproduces by budding.
Other genera are Aglauropsis, Gossea and Gonionemus; the last named bears adhesive suckers on the tentacles.
In Gonionemus, however, the concrement-cells are endodermal.
" Preliminary Note on the Life-History of Gonionemus," Journ.