108 



TUBULIPORA OBELIA. Encrusting, calcareous, ad- 

 herent throughout; cells tubulous, disposed in a radiating 

 manner, generally semi-circular. 



Tubulipora obelia, Johnston's Brit. Zooph., p. 269, pi. 30, 

 figs. 7 and 8. 



Hob. On stones and shells from deep water, common, 

 from the Ram Head to the Deadman. 



This is entirely an encrusting species. It is circumscribed 

 in its base, and semi-transparent. The tubes are distant, 

 recumbent, tubulous, and radiating from several centres, with 

 semi-transparent inter-tubular spaces. The tubes are most 

 commonly recumbent, as just described, but differ in their 

 appearances; sometimes they are erect, at others semi- 

 erect, and again either prominent or immersed ; and in some 

 specimens all these varieties occur together. 



TUBULIPORA HYALINA. Encrustinz, semi-transpa- 

 rent, membrano-calcareous ; cells distant from each other, 

 tubular, erect, arranged in one or two circular rows round 

 a plain centre ; apertures, unarmed and frosted. PI. xix., 

 fig. 6. 



Tubulipora hyalina, 9th Annual Report of the Royal 

 Cornwall Polytechnic Society, p. 73. 



Hab. On Fucus palmatus, rare. Polperro. 



This small species encrusts the margins of sea-weed in 

 patches of about the diameter of a pea. The tubes are 

 distant, erect, immersed in the surrounding structure, of 

 equal diameter throughout, and arranged in one or two rows 

 round a plain centre; sometimes there are a few cells ir- 

 regularly scattered in the centre, but separated from the 

 external set by a plain surface. The apertures are even, un- 

 armed, and of a milky appearance. In the Report of the 

 Royal Cornwall Polytechnic Society, I have refered this 

 species to the Berenicea hyalina of Fleming and Johnston, 

 though I had doubts of its correctness ; since then the latter 

 of these Gentlemen has informed me that his species is not 

 a Tubulipora; this therefore is a new species; the specific 

 name of Hyalina is retained as descriptive of its general 

 appearance. 



DISCOPORA. Larmarck. 



Generic Character: Polypidom calcareous, adherent through- 

 out; the base a circumscribed crust ; the cells coalescent, 

 indistinctly quincuncial, tubular, erect, with a round pa- 

 tulous terminal aperture without an operculum. Polypes 

 ascidian. 



