- 338 — 



I have met with this species growing in the outer walls of Chætop- 

 teris plumosa, Sphacelaria radicans and Sphacelaria britannica. 

 NW. Icel. Prestsbakki, Broddanes. 

 SW. Icel. Reykjavik (G. 0.). 



Chlorochytrium Schmitzii Rosenv. Grl. Havalg. p. 964, Deux. Mém. 

 p. 119. 



To this species I have referred some specimens occurring in an old 

 crust of a Ralfsia collected by Ostenfeld at Reykjavik. The Icelandic 

 specimens are 40— 110 u long and M — lOfi broad, they are thus much 

 shorter than the Greenlandic plants, 

 which attain a length of 200 fjt 

 (Rosenv. 1. c). The shape of the 

 Icelandic plants is, as in the Green- 

 landic specimens, clavate or obovate, 

 and the chromatophore is irregularly 

 perforated with very small holes, but 

 in this respect they agree also with 

 the Greenlandic plants. I have seen 

 in Rosenvinge's original preparations 

 that the chromatophore of the Green- 

 landic plants is perforated in a resemb- 

 ling manner. The colour of the cell- 

 walls of the Icelandic plants does not change to blue at application of 

 chlor-zinc-iodide. 



SW. Icel. Reykjavik (G. 0.). 



Codioluin Petrocelidis Kuck. Bemerk, p. 259, fig. 27. 



The Icelandic specimens are 70 — 116 /i long (without the stalk) 

 and 30 — 65/7. broad. The upper end of the cells is sometimes furnished 

 with a papilla (cfr. Kuck., 1. c. fig. 27 L) and the stalk is either lateral 

 or terminal. Both the stalk and the membrane of the head do not turn 

 blue by chlor-zinc-iodide, whereas they turn red by ruthenium oxychloratum 

 ammonia, consequently they do not consist of a cellulose but of pectose. 

 The species occurs in the frond of Petrocelis Hennedyi and is met with 

 both in the lower litoral region and in the upper sublitoral region on the 

 stems of Laminaria hyperborea. 



SW. Icel. Skögarnes, Reykjavik. 



Codiolum gregarium AI. Braun, Alg. unicell. p. 19; Börgesen Fær. 

 Alg. p. 51 7. 



I have only found this species in one place in E. Iceland, where it 



Fig. 1. Chlorochytrium Schmitzii 

 K. Rosenv. Three specimens showing 

 the varying shape of the cell and the 

 perforations of the chromatophore. 

 (400: 1.) 



