VI.—The Morphology and. Development of the Free-swimming Sporosacs of the Hydroid Genus Dicoryne (including Heterocordyle)

Abstract

Hitherto there has been described only a single species—Dicoryne conferta (Alder)—amongst the Hydrozoa in which the reproductive body is a sporosac which becomes ciliated and free-swimming. We have found that another species which, as we shall show (pp. 269–271), must be named Dicoryne conybearei gives rise to reproductive bodies of this type, which, however, differ from those of Dicoryne conferta in several important respects. The free-swimming type of sporosac has not been the subject of close observation since 1872; we have therefore made as complete a study of the structure and development of the sporosacs, especially of D. conybearei, as material gathered from several sources would permit.