Hydromedusae with considerable variation in form, with umbrella usually deep bell-shaped; with gonads almost invariably situated on stomach, very rarely extending perradially on subumbrella; with or without ocelli; without statocysts. Hydroids always athecate.
* See Addenda, p. 444.
* See Addenda, P. 444. on Pteroclva.
* See Addenda, p. 444.
* See Addenda, p. 444.
* See Addenda, p. 444.
* See Addenda, p. 444.
* See Addenda, p. 444.
* See Addenda, p. 444, for an additional species.
* See Addenda, p. 444.
* See Addenda, p. 444.