76 CONFERVACE^. 



This species varies much in minor characters, but may generally be known by its 

 lubricous substance, brilliant colour, fastigiate tufts, and straight, much branched fila- 

 ments which radiate to every side from a common base, in a star-like manner. In the 

 young plant the tufts are less dense, the filaments nearly free from each other to the 

 very base ; but as the plant advances in age, root-like processes are developed along the 

 lower part of the filaments, while the tufts become matted together, sometimes into a 

 compact spongy frond. In very old specimens this condensation takes place throughout 

 the whole length of the filament, except in the very youngest ramuli. The tufts are 

 from two to four inches in height, hemispherical, or variously divided into two or more 

 hemispherical or flabelliform lobes, and are generally level-topped. They are composed 

 of many parallel, much branched, capillary filaments, of nearly equal diameter from base 

 to apex ; the branches all very straight and erect, repeatedly but most irregularly 

 divided, and set with lateral, erect, straight ramuli, which are nearly as robust as the 

 branches from which they spring, and very obtuse. Toward the base of the filaments 

 the articulations are once or twice as long as broad ; a little farther up they are three 

 to four times ; and in the young branches and ramuli six to eight or twelve times as 

 long as broad. In the state or variety called C. centralis they are uniformly short 

 throughout except in the very young tips. The endochrome is dense and granular, and 

 recovers its form on being moistened after having been dried. The colour in general 

 is well preserved in drying, in which state the tufts retain much of their gloss, and 

 closely adhere to paper. 



Authors have made several species out of what we regard as simply C. arcta in 

 different stages. Thus C. vauchericeformis is the young, half-developed form ; C. arcta-, 

 Auct. the middle stage ; and C. centralis the old plant, where the matting together of 

 the threads has been carried to an extreme point. Other species of Kiitzing's section 

 Spongomorpha might probably be added to these synonyms A fragment of C. scopce- 

 formis, Rup. from Russian America, sent to me by Dr. Ruprecht himself seems to belong 

 to one of the spongy forms of this species. C. arcta is perennial ; and specimens 

 collected in the same locality at different seasons will be found to put on, successively, 

 all the characters attributed to the three principal forms indicated above. 



6. Cladophora lanosa, Roth. ; tufts dense, globose, small, fastigiate, yellow-green ; 

 filaments slender, irregularly much branched ; branches straight and virgate, erect, 

 patent ; ramuli few, scattered, erect, straight ; axils acute ; articulations in the lower 

 part twice, in the upper six to eight times as long as broad. lioth. Cat. Bot. 3, p. 291, 

 /. 9. E. Bot. t. 2099. Lyngb. Hyd. Dan. t. 56. Kutz. Sp. Alg. p. 420. Harv. 

 Phyc. Brit. t. 6. Wyatt, Alg. Damn. 194. 



Hab. On the smaller Algae, and on Zostera ; generally epiphytic. Boston Bay, Mr. 

 G. B. Emerson, (v. v.) 



Tufts rarely more than an inch in diameter, globose, dense, formed of many filaments 

 radiating from a common base. These filaments are at first separate, but at length by 

 means of rooting processes issuing along their sides, they become somewhat interwoven 



