HASSALLIA. 233 



Hal. On heath, sphagnum, &c., on the Pentland Hills, 

 found by Dr. Greville. 



" Forming a short brownish shaggy stratum, overrunning 

 the plants on which it grows. Threads suberect, giving out 

 in a proliferous manner short, very obtuse, branches of a beau- 

 tiful golden yellow brown. Two sometimes spring from the 

 same point. The walls of the threads are very thick. Spo- 

 rangia annuliform, green, composed of a compact grumous 

 mass, or divided, especially in the older threads, into a single 

 row of distinct oblong granules. 



" This very beautiful Alga was communicated by Dr. 

 Greville to Sir W. J. Hooker, in whose Herbarium it is 

 marked by M. Klotzsch Dematium turfaceum Lk., which 

 there is every reason to believe is correct. Link appears to 

 have been acquainted with the plant merely from the short 

 notice of it by Persoon in the f Mycologia Europaea.' Fries 

 tells us expressly, ' Syst. Myc.' vol. ii. p. 603. ad not., that it is 

 an Alga. It is indeed a true Scytonema, which bears much re- 

 semblance ivPetalonema alatum, though it wants the character- 

 istic feature of that very curious production. Radulum ater- 

 rimum of Fries, of which specimens are published in ' Scleromy- 

 cetes Sueciae', and to which Persoon's var. cornutum is referred, 

 is altogether different, and truly a fungus." M. J. B. 



This beautiful species bears some resemblance to H. ocel- 

 latum and still more to H. compactum ; the cells, however, 

 are rarely beaded, as they invariably are in both those spe- 

 cies. It is no doubt distinct from either, the branches are 

 generally single. 



4. HASSALLIA ? BYSSOIDEA Hass. 

 Plate LXVII. Fig. 5. 



Char. Filaments minute, erect, simple, of equal diameter, fas- 

 ciculate, obtuse, forming an unequal blackish crust. Striae 

 very close and evident. 



Scyt. byssoideum Berk., Glean. Alg. t. 19. f. 1. ; Harv. 

 Hook. Brit. Fl. p. ii. p. 366. ; Harvey, in Manual. 



