300 ULVACEiE. 



Merisviopedia punctata Jenner, in Fl. of Tunbridge Wells. 



Gonium tranquillum Ehi\, Die Infus. p. 57. t. iii. f. 3. 

 Hab. Ashdown Forest, Cold Bath Spring, &c. : Mr. 



Jenner. 



I am not at all acquainted with this pretty production ; it 

 doubtless, however, belongs to the family of Ulvacece, and 

 my Ulva binalis may possibly be identical with it. 



41. TETRASPOKA Link. 



Char. Frond either tubular, injlatcd, or Jlat, gelatinous. 

 Cells mostly arranged in fours. 

 Derivation. From rsrpa, four, and crTropa, a seed ; in allu- 

 sion to the arrangement of the cells. 



This genus seems to me to be wholly unnecessary : it ought 

 either to merge into Ulva, or else several species now asso- 

 ciated with that genus should be removed from it and placed 

 in Tetraspora. All the characters of the genus Tetraspora 

 may be found in one or other species of Ulva, and especially 

 that of the quaternate arrangement of the granules, or perhaps 

 more strictly speaking, the cells, from which the generic de- 

 nomination is derived. 



1. Tetraspora lubrica Ag. 

 Plate LXXVIII. Fig. 10. 

 Cha7\ " Frond quite simple, tubular, sub gelatinous, waved 

 and serrated,^^ 

 Harv. in Hook. Brit. Flor. vol. ii. p. 313. ; Harvey, in 



Manual, p. 176. 

 Hab. Hellesdon, Norfolk : Sir IF. J. Hooker. Appin : 

 Captain Carmichael Castlemartyr, Cork : Miss Ball. 

 Malahide : Mr. Moore. Aberdeen : Dr. Dickie. In an 

 old quarry above Cromlyn Bog, Swansea : J. IV. Gutch. 

 Tunbridge Wells ; Mr. Jenner. 

 The freshwater Ulvacea have not as yet been studied with 



