362 Marine Algae, of Berwick-on-Tweed. 



The primary filaments of this species spread horizontally, and, 

 becoming united to one another, form disc-like or irregularly 

 shaped expansions, usually composed of two layers of cells, from 

 which arise the short, simple secondary filaments and shortly- 

 stalked plurilocular sporangia. The articulations of the upright 

 filaments are about as long as broad — those of the decumbent 

 filaments a little longer. 



To follow PETROCELIS, p. 313. 



ACTINOCOCCUS, Ktz. 



Actinococcus roseus (Suhr.) Ktz. 



Phycol. Gen., p. 177, tab 45, fig. iv. — Eivularia rosea, 

 Suhr. sec. Ktz. 

 Descr. et Fig. Actmococcus roseus, Ktz., I.e. 



Syn. „ „ Ktz., Tab. Phycol. i., t. 31, fig. n. ; 



Ktz., Spec. Alg., p. 534; /. Ag., Spec. Alg. ir., p. 489 ; J. Ag., 

 Epicr., p. 375 ; ReinJce, Algenfl. der west. Ostsee, p. 21. 

 Hah. Forming nearly spherical masses on the fronds of Phyllophora 



Brodiwi. Hare. Berwick Bay, Burnmonth. 

 A true vegetable parasite, which is commonly taken for the 

 fruit of Phyllophora Brodiai. The frond is composed of two 

 parts, one of which consists of large, nearly colourless, oval or 

 irregularly shaped cells extending into the tissues of the infected 

 plant ; the other portion is composed of small, cylindrical, rose- 

 coloured cells formed into filaments, which are densely packed 

 together in a colourless jelly, constituting the cortical portion of 

 the frond. 



To follow GELIDIUM, p. 346. 



CHOKEOCOLAX, Eeinsch. 



Choreocolax polysiphoni^:, Eeinsch. 



Contrib. ad Algol, et Fungol. i., p. 61, t. 49, fig. a. 

 De.sc?-. Choreocolax polysiphonise, Reinsch., I.e. 



Fig. ,, n Farlow, " On some new or imper- 



fectly known Algae of the United States." Bulletin of the 

 Torrey Botanical Club, vol. xvi., no. 1, pi. 87, fig. 3. 

 Hah. Parasitical of Polysiphonia faxtigiata. Tetraspores, Nov. 1889. 

 Bare, Berwick Bav, 



