108 



TUBULIPORA OBELIA. Encrustins:, 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. 



Hab. 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, witli 

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

 comm.only recumbent, as just described, but differ in their 

 appearances; sometimes they are erect, at others semi- 

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

 specimens all these varieties occur togetlier. 



TUBULIPORA HYALINA. Encmsfinjr, 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 tiie 

 externiil set by a plain surface. Tlie 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 ot Fleming and Johnston, 

 though I had doubts of its correctne^s ; since then the latter 

 of these Gentlemen has informed me that his species is uot 

 a Tubulipora; this thereibre is a new species; the spceilio 

 name of Hyalina is retained as descriptive of its general 

 appearance. 



DISCOPORA. Lannaick. 



Generic Character : Polypidom calcareous, adherent through- 

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

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

 tulous terminal aperture without an operculum- Polj pes 

 BBcidian. 



