ESCHARID.E I FLUSTRA. 345 



Attains a height of four or five inches, very bushy, of a straw- 

 colour, smooth, varnished when dry, rather thin in texture, origi- 

 nating from a matted base formed of capillary fibres, which, by their 

 union, compose a short stem that divides, after a dichotomous man- 

 ner, into numerous flat narrowish segments, either linear or dilated 

 upwards. From the edges of these there often sprout out wedge- 

 shaped leaflets, affixed by a small pedicle, simple at first, but after- 

 wards deeply bifid : the ends of all the segments are abruptly trun- 

 cate. Cells linear-oblong, their septa unarmed, usually marked with 

 a black dot towards the centre, which seems to be the remains of 

 the shrivelled polype, and at some seasons covered with a hood-like 

 operculum. Wall of the cell thin and hyaline, with a small circu- 

 lar galeated aperture. 



The Porus cervinus minor of Marsilli, Hist. Phys. de la Mer, p. 

 63, pi. vi. figs. 23, 24, is surely identical with Flustra truncata. 



* * Foliaceous, with cells on one side only. 



4. F. CARBASEA, cells oblong, narrowed and truncate below, 

 the margin toothless. Dr. Skene. 



PLATE LXIII. FIG. 1, 2. 



Porus cervinus, Mars. Hist. Phys. de la Mer. 64, pi. 6, fig. 25, 26. Eschara pa- 

 pyrea, PaU. Zooph. 56. Flustra carbasea, EUis and Soland. Zooph. 14. pi. 3, fig. 6, 

 7. Turt. Gmel. iv. 663. Jameson in Wern. Mem. i. 563. Turt. Brit. Faun. 

 209. Stew. Elem. ii. 436. Lam. Anim. s. vert. 2de edit. ii. 221. Plan. Brit. 

 Anim. 535. Grant in Edin. New Phil. Journ. iii. 111. Johnston in Trans. Newc. 

 Soc. ii. 264, pi. 9, fig. 4. Templeton ut sup. cit. 469. Roget Bridgew. Treat, i. 

 165, fig. 63, 64 ; and 172, fig. 69, 70. Dalyell in Edin. New Phil. Journ. xvii. 

 413 ; and in Rep. Brit. Assoc. an. 1834, 603. Flustra papyracea, Esper Pflanz. 

 Flust. tab. 2, fig. 1-3. 



Hah. On shells from deep water. From Aberdeen, Skene. Leith 

 shore, Mr. Parsons. Not unfrequent at Seaton, Hartlepool, Whit- 

 burn, and other places on the coast of Durham, J. Hogg. Coast of 

 Berwickshire, not uncommon, G. J. Coast at Bootle, rare, Mr. Tu- 

 dor. Ireland, Templeton. Of rare occurrence on the Dublin coast, 

 and I have never met with it elsewhere, W. M'Calla. 



Polypidom frondose, fixed by a small disk, narrow at the base 

 with thickened margins, dilating upwards and becoming very broad 

 in proportion to the height, which at most is about two inches, thin, 

 yellowish-brown, deeply divided, the segments broad and somewhat 

 rounded on the apex. Cells on one side only, large, and smooth. 



