294 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 4 



PLATE 22 



Fig. 1. Hydractinia prolifica, new species 



a. Natural size. 



b. and c. Nutritive zooids. 



d. A generative zooid. 



e. A group of spines. 



f. A single spine. 



Fig. 2. Ectopleura media, new species 



a. Natural size. 



b. Hydranth with gonophores. 



c. Portion of gonophore with developing medusa buds. 



d. A fully developed medusa bud. 



