290 .loHS. HOYI-: 1'i;ti:hsi;\ 



1 have exaniiiied otlicr samples from Gcysir, colfccled by Slcenstrup, 

 and I find, like (iomonl. llial tlu'v resemble .S. arenaria closeh' evcn 

 tliouj^h tlic dclcrminalion is not (iiiilc cciiain. Esperially tlie ape\ of 

 tlic trichome docs not seem to be so distinctly conital as llie one li- 

 j^iircd in Gomont (1. c). 



S. arenaria is only recorded from a few localities; but they are scat- 

 tcred over the foiir eontinents, so that ils distribution is undoubtedly 

 very wide. It seems to grow exclusively on earth and rocks. 



In the sample from Vestdalur it grew togcther with Dcsmoncma 

 Wrangelii and (iloeocapsa Magma var. Itzigsohnii. 



Schizothrix Friesii (Ag.) Gom. 



Gomont, Monogr. 1 p. 316, pi. IX, Jigs. 1—2. 



E. Icel. Vestdalur at ScyftisfjonVir, among mosses on earth Vt 1914. 



— N. \V. Icel. Botn in Geir^jofsfjonVir, lake, temp. 10° ^^7 1915 ,H. J.)! 



— S. Icel. Laugarvatn. On earth near little hver ^^/s 1914. 



Area: Eur., Afr., Am., Austr., Antarctic continent. 



S. Friesii occurs generally on earth, rocks and similar localities, has 

 also been found on trunks Wille 1914 p. 10. The Icelandic localities 

 are of the same kind excepting the sample from Geir|>j6fslj6ri^ur which 

 is recorded from a lake, i. e. in the water. In none of the three sam- 

 ples fasciculi erecti were found, these being thus undeveloped specimens; 

 but the trichomes and the sheaths are so characteristic that the species 

 can be dctermined on the basis of these alone (cf. Gomont 1. c). 



Schizothrix Mlilleri Niigeli. 



Gomont, Monogr. I ]). 321, pi. X, figs. 5—7. 



\V. Icel. Rej'kholt, on Moss over the afllux to Snorralaug from 

 Skrifla, er. 5 cm. over the surface of the water, temp. 42 '^ V« 1914. 

 Area: Eur., As., Am., Lappland. 



In the specimen to hånd of S. Mulleri the diameter of the trichomes 

 was 6—7.6 //, i. e. somewhat smaller than the typical oncs. Furthermore 

 only one trichome is as a rule found in each sheath; it therefore ap- 

 proaches f. lijiujlyyoidea Gom. I. c. and Gomont 1899 p. 27j. 



The species may be found on earth as well as on slones and rocks, 

 at and in water, and Gomont arrived at the conclusion that the more 

 dry the species grows, the shorter and the more bent do the tlireads 

 become, whereas these, whcn it grows in water, become elongated and 

 nearly always contain but one trichome. The Icelandic specimen grew 

 on moss that was, to be true, very moist, but which nevertheless oc- 

 curred above the surface of the water. Tliis does not seem exactly to 

 confirm Gomonl's explanation. 



Schizothrix Heufleri Grun. 



Gomont. Monogr. I p. 325, pi. XI. figs. 7—8. 



E. Icel. Fljotsdalur, rocky wall, forming thin black layers '% 1914. 

 Area: Fur. 



