Studies in Australian athecate hydroids. No. IV. Development of the gonophores and formation of the egg in Myriothela harrisoni, Briggs

Abstract

The following account of the development of the gonophores and the formation of the egg in Myriothela harrisoni is based on a single female and several male specimens collected on the undersides of rocks below low-water mark at Bulli. forty miles south of Sydney. Although M. harrisoni is a dioecious form, it bears a distinct resemblance in its gross morphology to M. cocksi, which occurs under similar conditions on the coasts of Great Britain and western Europe. Both species have a chitinous investment by perisarc covering the hydrorhiza and forming a firm basis of attachment to the surface of the sub-stratum. This likeness is further emphasized by a study of the development of the gonophores and the formation of the egg, which follows through a series of stages very similar in their general details to those I have already described for M. australis.