CRYPTOGAMIA ALG.E. 250 



distinct partitions Bot. Gall. iL 987- Oscillatoria muralis, HOOK. 

 Scot. ii. 79. GREV. Fl. Edin. 304. Conferva muralis, Eng. Bot. 

 t. 1554. DILLW. Conf. 39. t. 7. 



If af>. On damp walls and old wood works in wide green 

 strata. 



" Of all vegetable productions this is perhaps one of the most 

 common upon damp walls, stones, and especially neglected 

 shady gravel walks. The dark areas in which the inhabi- 

 tants of crowded cities gasp for air, become verdant in the 

 wet months of winter with this Conferva, whose effects on 

 the atmosphere may perhaps be as beneficial as those ob- 

 served by l)r PRIESTLEY in the species produced in cor- 

 rupted water." SMITH. 



163. BANGIA. 



1. B. fusco-purpurea, filaments capillary, simple, straight, green- 

 ish-brown or purplish ; granules arranged in transverse lines. 

 GRKV. F I. Edin. 301. Alg. Brit. 177. Conferva fusco-purpurea 

 et atro-purpurea, DILLW. Syn. 54. t. 92. and t. 103. Eng. Bot. 

 t. 2055. 



Hub. On rocks at high-water mark, or even above it. 

 Near the Coves, abundant. 



Grows in smooth even layers, and much resembles human 

 hair, a resemblance which it well preserves when dried. 

 The filaments are of two kinds, one larger, soft, and of a 

 loose texture ; the other of a darker colour, much slen- 

 derer, and marked with close set granules, arranged in re- 

 gular transverse rows. There are two varieties on our 

 coast ; the first is olive or greenish-brown, with filaments 

 about an inch long; the other is of a beautiful purplish- 

 red colour when dried, and often exceeds 6 inches in length. 

 The latter is the Banyia otro-purpurea of AGARDH, the 

 Cadmus violmwt of MOUGEOT and NESTLER, No. 89.5. ; 

 but, according to j)r GRKVILLE, the characters which dis- 

 tinguish it from the first are not suilicient to constitute a 

 .species. 



2. B. LaminaritBj olive-green ; filaments tufted, short, simple, 

 continuous, with minute grains disposed in transverse lines. 

 GUEV. FL Edin. 302. LYNGH. Uydroph. Dan. 84. t. 24. 



Hab. Parasitical on the frond of Laminaria esculenta, not 

 common. 



