748 SOME NEW AND RARE HYDROIDA IN THE AUSTRALIAN MUSEUM, 



OBELIA AUSTRALIS, von Lendenfeld. 

 I.e. p. 604. (See page 753). 



DIPHASIA RECTANGULARIS, von Lendenfeld. 

 I.e. p. 914, PI. XLL, figs. 6-8. 



This is synonymous with Idia pristis, Lamx. Fig. 7 shows 

 part of a pinna with the hydrothecae separated, but there is 

 nothing of the kind in the type specimens, which are quite 

 similar to that figured in the " Catalogue." The gonothecae also 

 agree with my former specimens, and not with Dr. von Lenden- 

 feld's figure. 



EUCOPELLA CAMPANULARIA, von Lendenfeld. 

 (See page 751). 



A few other species were represented, but the specimens were 

 too fragmentary, or not sufficiently well preserved, to be of 

 much value. 



CERATELLID^E. 



Hydranths naked, sessile on processes of a chitinous reticu- 

 lated polypary, tentacles all capitate, scattered irregularly over 

 the body. Gonosome unknown. 



CERATELLA FUSCA, Gray. 



Hydrophyton forming a much ramified compressed structure, 

 resembling a Gorgonian coral ; polypary chitinous, of a dark brown 

 colour, and of a finely reticulated structure, the main stem finally 

 becoming very thick and irregular in form ; branches gradually 

 smaller towards the ends, very numerous and crowded : hydro- 

 phores (bracket-like projections of the hydrocaulus, which support 

 the hydranths) arranged in a somewhat irregular sub-spiral manner 

 round the branches, formed by slightly radiating ribs united by 

 perforated laminae, the ribs projecting at the outer margin ; meshes 

 of the polypary filled with ccenosarc. ttydranths ovate, sessile 



