270 Z. ASCIDIOIDA. Discopora. 



Obelia tubulifera? Blaiiw. Actinolog. 424, pi. 71, fig. 1. Lam. knim. 

 s. Vert. 2de edit. ii. 246 O. tubifera? Gray, Zool. Misc. 35. 



Hab. In the harbour of Kinglade near Cork, parasitical on a Pinna, 

 Miss Elliot. In deep water at Scarborough, on Modiola vulgaris, 

 rare, 3Ir Bean. 



Crust rather thin, entirely and very closely adherent, chalk- white, 

 even, spreading in somewhat circular expansions : the cells alter- 

 nate, rather distant, rowed, radiating from several centres, divided 

 by paler lines, horizontal, tubulous, mostly immersed, the mouths 

 raised with a wide round oblique plain aperture. 



This description is taken from a specimen in the collection of Mr 

 Bean. It adheres to the shell of Modiola vulgaris, and is six-tenths 

 of an inch in one direction and nearly five-tenths in another. The re- 

 semblance between it and Obelia tubulifera is fully sufficient to war- 

 rant the conjecture of their identity, for the differences which the 

 student will detect between our figure and that of Laraouroux, copied 

 by Blainville, are probably the mere peculiarities which mark the in- 

 dividuals of a variable species. Of Obelia as a genus, Blainville re- 

 marks that it is truly unimportant, scarcely differing from Tubuli- 

 pora ; and the merging of them into one seems therefore a natural 

 union, while at the same time we get quit of a name that has been 

 also applied to some Medusae. 



Of Obeliae generally Mr Templeton says, " There are at least^fe 

 native uncharacterised species, on small corallines and shells, very com- 

 mon in protected bays" of the Irish coast. Mag. Nat. Hist. ix. 470. 

 To determine these will be the pleasant duty of the naturalists of that 

 country. 



31. Discopora,* Lamarck. 

 Character. Polypidom calcareous, adherent throuylwut ; 

 the base a circumscribed crust ; the cells coalescent, indistinctly 

 quincuncial, tubular, erect, with a round patulous terminal aper- 

 ture without an operculum. — Polypes unknown. 



1. D. HispiDA, crust spreading subcircularly, roughish, wavy 

 or ridged ; the cells erect, obscurely voiced, with one larger and 

 two minute denticles on the side of the apertures.— T>v Fleming. 



Plate xxxi. Fig. 9 — U. 



Discopora hispida, Flem. Brit. Aiiim.530 Le discopore h^visse, Bluinv. 



Actinolog. 446. 

 Hab. " On Corallines from deep water. Zetland," Fleming. 



' From discus, a flat plate or disk, and ■n-opoi. 



