Flustra. Z. ASCIDIOIDA. 287 



F. aviculaire, Bluinv. Actinolog. 451 F. angustiloba, Lam. Anim. 



s. Vert. ii. 158. 2de edit. ii. 222 F. capitata, Hogg's Stock. 36. 



Crisia flustroides, ZamoMr. Corall. Flex. 141. Corall. Gl. 



Hab. Attached to other corallines and old shells in deep water. 

 Torhay, Dr Coldstream. Cullercoats, Northumberland, Mr Alder. 

 Berwick Bay, G. J. Cork harbour, J. V. Thompson. 



Usually about an inch in height, csespitose and fan-like, or spread 

 out circularly, of a cinereous colour, merabrano-calcareous, brittle 

 when dry, deeply divided in a dichotoraous manner into narrow thin 

 plane segments, truncate at the end, formed of four or five series of 

 oblong cells, capped with a hollow globose pearly operculum seated 

 between the spines, of which there is one on each side of the circu- 

 lar aperture. The opercula are so numerous that they give to the 

 upper surface the appearance of being thickly strewn with orient 

 pearls : the under surface is even and longitudinally striated, the 

 number of striae corresponding to the number of rows in which the 

 cells are disposed. 



7. F. MURRAY ANA, cells multiserial, ovate, the margin armed 

 icith 6 or 8 spines shorter than the diameter of the cell. Mr Bean. 



Plate xxxvi. Fig. 5, 6. 

 Flustra Murrayaiia, Bean, MSS. named " after Dr Murray, a scientific and 

 zealous naturalist of Scarborougb." 



Hah. In deep water. Scarborough, very rare, Mr Bean. 



This pretty species grows in entangled spreading masses which are 

 rooted to the object of attachment by numerous long thread-like tu- 

 bular fibres, wrinkled when dry, and apparently always pullulating 

 from the side or inferior surface of a marginal cell. Polypidom 

 scarcely an inch in height, of a light colour and thin membranous 

 texture, dichotomous, spreading, the segments plane, narrow wedge- 

 shaped, truncate, the upper surface roughish with the cells, which are 

 disposed in the usual quincuncial manner, but are more elevated than 

 in any other species ; the under surface glistening, striate : cells uni- 

 lateral, so large that their figure is perceptible to the naked eye, ovate, 

 truncate above with a short hollow spinule at each angle, and there 

 are from 4 to 6 rather longer spinules protecting the margin of the 

 elliptical aperttire — I have seen only Mr Bean's fine specimen, which 

 is accurately delineated in our figure. The species is very distinct 

 from any hitherto described. 



* * * Crustaceous. 

 8. F. MEMBRANACEA, cells ohlong, icith a short blunt spine at 

 each corner. J. Ellis. 



Plate xxxvii. Fig. 1, 2, 3. 



