/4 BRITISH SEA-WEEDS. 



springing at right angles from the expansion formed by the 

 inner, both series united by gelatine, into a compact, cushion- 

 like mass. Spores oblong, affixed either to the erect or to 

 the spreading threads. — Myrioistema., from the Greek mu- 

 rios, numberless, and nema, a thread. 



This is another genus of minute parasites, smaller 

 even than the Elachista. 



Myrionema strangulans. Choked Myrionema. 



Patches at first only dark-brown spots, consisting of the 

 spreading threads, afterwards the erect threads are de- 

 veloped, and the patches become convex and gelatinous. 

 Spores on short stalks springing from the spreading threads. 



This species grows on Ulvce and Enter omorphce. 



Myrionema Lechlancherii. Lechlancher's 

 Myrionema. 



Patches orbicular; the spreading threads, which are de- 

 veloped first, as in the last species, radiate from a centre, 

 the erect threads are densely set together, and are longest 

 in the middle of the patch, whence they gradually become 

 shorter as they approach the side. Spores on long stalks. 



This species grows on Rhodymenia palm at a, and 

 sometimes on Viva. In autumn the fronds of the 

 former are frequently covered with dots, which appear 

 to the naked eye to be but the first symptoms of decay, 

 but which when examined under a moderately powerful 

 microscope exhibit the beautiful structure of this minute 

 parasite. 



Myrionema punctiforme. Dot-like Myrionema. 



Patches very minute, globose ; spreading threads forming 

 a small base, from which the erect threads radiate. Spores 



