266 NEMATOGEN.E. 



aernginous green, joints shorter than broad ; sliuaths thick, 

 golden brown, often encrusted with deposit of lime. 



SIZE. Trichomes '008 mm., including sheath -01 mm. 



Kirch. Alg. Schl. 225. Rabh. Alg. 'Ear. ii.. 247. 



Scytonema Juliannm, Wittr. & Nordst. Alg. Exs.,-No. 273 a. 



Drilosiphon muscicola, Kutz. Sp. 302. 



Oscillaria cyanea, Hass. A.lg. 248. Eng. Fl. y., 374. Harv. 

 Man. 163. 



Conferva cyanea, Eng. Bot. ii., t. 2578. 



Humid a cyanea, Gray. Arr. i., 282. 



On walls, stones, overrunning moss, &c. 



Found on the walls of warm houses in the Royal Botanic Gardens at 

 Kew, and in Regent's Park. This is evidently the Conferva cyanea of 

 English Botany found on damp walls in churches, &c. " On the wall it 

 is conspicuous for its light sky-blue colour, like some sort of Jhi'-or. 

 Under a high magnifier, and when moistened, it is found to consist of 

 minute even simple entangled threads, coated with a frequently inter- 

 rupted covering 1 of a dull glaucous green hue, under which the thread 

 itself appears of a lighter glaucous bluish colour, very even in thickness, 

 and surface consisting of scarcely distinguishable joints about as broad 

 as they are long." Smith. 



Bornet and Thuret refer this to a variety of Scytonema Hoffmanni, 

 whilst Kirchner retains Meneghini's specific name, which Thnret thinks 

 to belong to Scytonema ocellatum, Lyngbye. 



Plate CPl.fiy. 1. a, trichomes X 400; 1>, portions of same X 400 ; c, 

 hormogones X 400. 



\ 



Scytonema interruption. Thw. 



Intense blue-green, forming a stratum of the same colour ; 

 sheath cellular, and furnished throughout its entire length with 

 numerous branched and anastomosing rootlets ; trichomes dis- 

 tinctly annulate, interrupted here and there by heterocysts, 

 branches in pairs arising from the protruded trichome. 



SIZE. Nowhere stated. 



Rhizonema interruptwn, Thwaites in Eng. Bot. ii. Stipp., t. 

 2954. 



Calothnx interrupta, Garni. Eng. Fl. v., 368. Harv. Man. 

 158. 



Stigonema interruption, Hass. Alg. 229, t. 69, f. 2. 



In wet heathy places, coating mosses, &c. 



We have seen no specimen of this, which is evidently a close ally of 

 /& cinereum. The figure is reproduced from English Botany. 



Plate CV1. fig. 2. Scytonema interntptum, after the figure t. 2954, 

 English Botany. Considerably magnified, presumably about 360 diam. 



