HARDWICKE'S SCIENCE-GOSSIP. 



275 



42. B. 7tiz'ca, Rabenh. 



Lcptoncma nivcum, Rabenh. 



Threads very slender, indistinctly jointed, i-l J /ti 

 thick (according to Rabenhorst), forming undulated 

 %voolly tufts of a chalk- white coloui-. 



In sulphur springs. (Fig. 215, /'.) 



In Wartmann and Schenk's " Schweiz. Kryptog.," No. 639, 

 this species is published under the name oi Symphyothrixnivca, 

 Briigger. Both the names given above are cited as synonyms, 

 l>ut only pro parte. From the label attached I extract the 

 following observations: — "Threads inarticulate and motionless, 

 only -j^Vo to nr'iTj'" thick (='5 — 1*3 y.), parallel and much 

 entangled, in penicillate tufts, 'strings, and sheaves'of very un- 

 equal size, which are surrounded by a common, homogeneous, 

 colourless gelatine." 



tions as long or half as long as broad. Threads 5-6 J /x 

 thick, forming thin, araclinoid, chalk-white gelatinous 

 membranes. 



In sulphur springs and marshes. 



45- B.pellucida, Cohn. 



Threads about 5 jx thick, motile, distinctly jointed, 

 with rounded ends ; articulations almost as long as 

 broad, translucent, containing but few granules. 



In an aquarium with sea-water. (Fig. 214.) 



46. B. viirabilis, Cohn. 



Threads very thick, motile, bent and curled in 



Fig.'2i6. — a, Cladoihrix dichoioma, X 100 ; h, a part of the same, 

 showing the false dichotomy, X 600 (after Cohn). 



Fig. 218. — Mycoiwstoc gregarium. a, gelatinous sphe- 

 roids, containing the threads ; b, a spheroid in the act 

 of division ; c, the threads separated ; d, the threads 

 breaking up into ring-shaped pieces. 



Fig. 217. — Cladothrix Forcieri, X 600; 

 a, the threads embedded amongst Micro- 

 cocci (after Cohn). 



Fig. 219. — Myconostoc gregarluiii, X 1300 ,'after 

 Lankester, who considers it a zooglcea form of 

 Spiriilum iindula. 



43. B. leptomitiformis (Menegh.), Trev. 



Oscillaria leptomitifonnis, Menegh. 



Threads very slender, indistinctly jointed, about 

 I'8-2*5 ^ thick, forming a thin chalk-white slimy 

 layer. 



In sulphur springs. (Fig. 215, c.) 



44. B. arachnoidea (Ag.), Rabenh, 



Oscillaria arachnoidea, Ag. 

 0. versatilis, Kiitz. 

 Threads pretty thick, distinctly jointed, strongly 

 motile, with rounded slightly curved ends. Articula- 



various ways, with rounded ends, distinctly jointed, 

 as much as 16 jx thick ; articulations about half as 

 long as broad, filled with numerous, pretty large 

 granules. Threads twisted round and entangled with 

 one another, forming a snow-white web of gelatinous 

 threads. 



With the preceding. 



Doubtful Species. 



47 



B. tigrina, Rabenh. 



Oscillaria tigrina, Romer. 

 Threads pretty thick, oscillating, distinctly jointed, 



