96 Proceedings of the Royal Society of Victoria. 



Clathrozoon wilsoni, Spencer. 



(Trans. Eoyal Soc. Yict., Vol. II, Part I.) 



This hydroid was represented only by the polypidom in the 

 collection which I received from Mr. Wilson ; other specimens, 

 which the same gentleman collected later on, and which included 

 the soft parts, were forwarded to Professor Spencer, who has 

 described them as the type of a new family. 



, n. yen., and sp. 1 



(Plate III., figs. 1, 2.) 



Hydi'ocaulus nine inches (or more) in height, consisting of 

 a stout monosiphonic stem with a few ascending branches, 

 nearly equal in diameter for the greater part of its length, not 

 distinctly jointed, very irregular in shape, being much swollen 

 about the origin of the polyp-tubes ; polyp-tubes given off on all 

 sides without any regular order, sometimes very. short, scarcely 

 projecting, but usually about as long as the diameter of the stem, 

 straight, or more often irregularly bent or twisted, terminating 

 in a stout annular thickening, darker in colour than the rest. 

 Hydranths unknown. 



Gonophores solitary, borne on peduncles which occupy tubes 

 like those of the hydranths. 



Hab.—Povt Phillip Bay (Mr. J. B. Wilson). 



The hollow stem averages about ^^^ to ^V of an inch in 

 diameter, but varies greatly at different points, owing mainly 

 to its inflated condition at those parts where the polyp-tubes 

 originate. The latter also are far from uniform in shape and 

 size, often having a distorted appearance, and being sometimes, 

 but not invariably, a little expanded at the summit. Here and 

 there the mai-gin, with its thickened ring, is duplicated, as in 

 many caliculate species. There are no hydrothecte, and I failed 

 to find any hydranths ; but one or two of the lower tubes bore 

 gonophores, which appeared to take the form of ovate or oblong 

 sacs, without openings at the summit, but were not in sufliciently 

 good condition to admit of their structure being accurately 

 determined. 



