Stigoneina.) ALGJE CONFEIIVOIDEJB. 363 



changed, in others they form a mass of larger granules than in the lines; 

 and some have a large oval seed, which often swells the joints. Traces 

 of unchanged lines occur, now and then, in the fructifying joints." 

 E. Bat. 



Tribe XVII. Oscillatorie^e. 



Plants green or brown, rarely purple, continuous, tubular, sel- 

 dom branched, though often agglutinated together, so as to appear 

 branched. Fructification; an internal mass, divided by transverse 

 septa, finally separating into roundish or lenticular sporidia. 

 — Fresh-water, marine, or on damp ground. 



71. Stigonema. Ag. Stigonema. 

 Filaments cylindrical, cartilaginous, branched, inarticulate, 

 including granules ranged in transverse dotted rings. — Name; 

 6-riyuiv, dotted, and v^/xa, a thread. 



1. S. atrovirens, Ag. (black-green Stigonema); tufted, branches 

 slightly divided slender attenuated subacute, rings three-dot- 

 ted. — Ag. Syst. Alg. p. 4:2. — Conferva atrovirens, Dillw. Conf. 

 t. 25. — Lichen pubesce?is, E.Bot.t. 2318. — Cornicularia pubes- 

 cens, Ach. — Bangia atrovirens, Lynyb. Uydroph. Dan. t. S5. 



Wet rocks in subalpine glens, common. — Forming broad, rigid, very 

 dark, loose tufts; filamenti divaricately branched; branches much nar- 

 rower than the stem, often furnished with a few slender, secund 

 ramuli. 



2. S. mammillosum, Ag. (mam mi Hated Stigonema); branches 

 simple incrassated fusiform densely manmiillose. — Ag. Syst. 

 Alg. p. 42. — Bangia ma/umillosa, Lynyb. Hydroph. Dan. t. 25, 

 (very bad.) 



Bottoms of alpine rivulets, Appin, Capt. Carmic/tael. Eagle's Nest, 

 Kiilarney, W. II. Harvey. — Forming continuous tufts, some inches in 

 diameter, softer and more flaccid than the last : branches of various 

 lengths, simple, fusiform, their diameter in the middle 2 — 5 times that 

 of the stem, densely mammillose on all sides, and not unlike the pickle 

 called <: girkins" under the microscope. The manWiilUe originate in the 

 central matter, and are protruded through the cuticle ; they are, doubt- 

 less, viviparous elongations of the granules. This supposed species, not- 

 withstanding its very peculiar character, is perhaps only a cane/// of the 



preceding, occasioned by a moister habitat. Lyiigbye's figure is very 



defective. 



3. S. pctnnifbrme, Haw. (crust-liAe Stigonema); filaments 

 dark-brown densely packed together much branched, branches 

 long fiexuoseobt use, rings I hree-dotted, — Scytonemapanniforme, 

 Cartn. MSS.—Ag, Syst. Alg. p. 39? 



On rocks at the mouth of the Spar c,i\c, Skye, ('"/>/. Cnnnic/iticl. — 



Patches indeterminate, crustlike, velvetty. "Filament* so close!) packed 



that only their apices are visible above the crust, very touch when dry, 



gelatinous when insist, cohering strongly together, much branched; 

 branches long and flexuose, divaricating, cylindrical, quite obtuse, not 

 tapered. Granules ternate, verj obvious in all the main branches, 

 distinct towards the apices. This entirely agrees in external chai 

 and ramification, with the Scytonema panniforme of Agardh : with an 



