Pro£, Allman on the Hydroida. 6l 



Campanulina repent, Allman, n. sp. 



Trophosome — Hydrocaulus springing from a creeping stolon- 

 like hydrorhiza, and consisting of numerous short simple stems, 

 each terminated by a polypite, and, along with these, other more 

 developed stems with alternate branches ; hydrothecse conical, 

 with the margin continued by a membrane which is cut into 

 deep acute segments, forming an operculum which closes over 

 the orifice of the hydrotheca when the polypite is withdrawn or 

 absent ; the hydrocaulus is distinctly annulated, but the hydro- 

 rhiza is smooth. Polypites very extensile, with about sixteen ten- 

 tacula, rendered nodulose in extension by irregular clusters of 

 thread-celU ; the tentacles during extension are held with the 

 alternate ones elevated and depressed, and are united at their 

 base by a very shallow web. 



Gonosome. — Gonangia large, borne upon the creeping stolon, 

 and occasionally also upon the hydrocaulus, about three timea 

 the length and breadth of the hydrothecse, in the form of an in- 

 verted cone slightly gibbous at one side near the proximal end, 

 and supported on the summit of a very short annulated pedun- 

 cle. Gonophores phanerocodonic ; medoss at the time of libera- 

 tion with four very extensire marginal tentacles, which are 

 nodulated by clusters of thread-cells. 



C. repent was found investing the surface of Sertularian Ily- 

 droids dredged from about 5 fathoms in the Firth of Forth. It 

 differs from C. acuminata, Alder, in the hydrotheca being 

 crowned by long, acute, converging segments, which on the re- 

 treat of the polypite form a true operculum, while the hydro- 

 theca in C. acuminata is merely contmued by a delicate collap- 

 sile and undivided membrane — as well as in the much slighter 

 development of the scarcely apparent web which unites the 

 bases of the tentacles, and in the fact that the medusa at the 

 time of liberation has four well-developed marginal tentacles, 

 while the medusa of C. aeummata has only two. Some of these 

 characters may possibly be regarded as pointing rather to a 

 generic than to a merely specific difference. (See my Synopsis of 

 the Campanularian Hydroids, 'Annals,' May 1864, p. 876.) 



In my Synopsis of the Tubularian Hydroids (p. 359), I pro- 

 posed the establishment of a new genus, under the name of 

 Heteractis, for the Corymorpha annulicomis of Sars. I had un- 

 fortunately overlooked at the time the fact that this name had 

 been already employed by the botanist for a genus of composite 

 plants — an inadvertence to which one of my pupils, Mr. W. R. 

 M'Nab, has since called my attention. I would accord- 

 ingly now propose that the new zoological genus, instead of 



