298 ULVACE2E. 



Limerick : W. H. Harvey. Near Ballycastle : Mr. D. 

 Moore. Roger's Tower on Castle an Dinas, near Gul- 

 vall ; and Bosigran Castle, near Morvah ; in both places 

 on granite : Mr. Borrer. Dublin Bay : Mr. Moore. 

 On damp shaded walls, on the ground ; frequent, near 

 Tunbridge Wells : Mr. Jenner. Walls of Chesterton 

 church, near Cambridge : Rev. Prof. Henslow. 



Having carefully examined numerous specimens which have 

 been sent me under the names of Ulva crispa and Ulva fur- 

 furacea, and not being able to detect the slightest difference in 

 the microscopic characters of these, I do not hesitate to unite 

 the two supposed species. 



The specific denominations of crispa and furfuracea are 

 both well expressive of the appearance of this species : the cells 

 are densely crowded together in the frond, so as indeed to 

 leave very narrow interspaces between the groups of cells, 

 which are usually composed each of about sixteen cells, 

 disposed in fours, and which from the compression one against 

 the other are rendered somewhat angular. The different 

 groups of cells are not disposed usually in linear series. 



3. ULVA CALOPHYLLA Spreng. 

 Plate LXXVIL Fig. 1. 



Char. Frond densely tufted, plane, linear, ligulate, attenu- 

 ated at base, often stipitate, longitudinally striate, each 

 stria marked with a series of bi-quaternate granules. 



Hook. Brit. Flor. vol. ii. p. 312. Bangia colophylla Carm., 

 in Grev. Crypt. Fl., t. 220. 



Hob. On damp stones, rocks, &c. ; Lismore Island, 

 Appin : Captain Carmichael. Near Limerick : W. H. 

 Harvey. Dublin : Mr. Moore and Dr. G. J. Allman. 

 North of Ireland : Mr. D. Moore. Oswestry : Pev. J. 

 Salwey. 



" This forms a bright green thin stratum. Frond minute, 

 three or four lines long, linear, strap -shaped, obtuse, tapering 

 at base, or suddenly contracted into a cylindrical stipes, much 



