46 BRITISH SEA-WEEDS. 



of Sea- thongs would be best translated by the latter 

 word, and that probably is correct. This genus con- 

 tains but one species. .,..,, 



Himanthalia lor.ea. Leather-thong Himanthalia, 



or Sea-thongs. 



. . ,; ..." 

 This is common on the Atlantic shores of Europe, 



and has been found on -the coast of North America. Its 

 chief peculiarity consists, in the very large proportion 

 that the spore-receptacles bear to the whole plant. 

 These are commonly three or four feet long, and are 

 said to attain a length of even twenty feet, while the. 

 little button frond is never more than an inch or an 

 inch and a half high, and about two inches in diame- 

 ter. Great diversity of opinion has been expressed as 

 to the duration of this plant, — some writers asserting 

 it to be annual, some biennial, and some even peren- 

 nial. My own recent observations of a very large num- 

 ber of growing specimens in early spring lead me to the 

 conclusion that the middle course is, as usual, the cor- 

 rect one, and that it is biennial. It certainly is not 

 annual ; but I am not prepared to say that it may not 

 be perennial. 



jo? tt'i ea ?'.:. ■ ■'- '•"~* - - ' tr 



Order II. SPOROCHNACE^E: 



Fronds without joints. Spores attached to external, jointed 

 filaments, either free or compacted together. 



Genus VII. DESMABESTIA. 



Frond linear, $ either thread-like or -more • or less flat,- 

 branched, witn a" single-tubed, jointed thread: running' 

 through it, when* young bearing marginal <tufts of branch- 

 ing fibres. Fructification unknown. : - v L ~ 



