282 



JOIIS. HOYK l'KTKHSKN 



Fif,' 4. 



Phormidiinu 



ramnsum 



n. sp. 



Apices of 2 



trichomes. 



(X1800). 



there can hardly W ;iiiy (|ucslion of :iiiy rlosc relationship. On llie 

 other Iland, tlu- liiclioiiu's aj^rec to soiiie exlenl witli lliose in /'. uririi- 

 ktlc West l'.)02 p. 248 ; howt'vcr. siich diirercnccs cxist 

 that I cannot tliink of identilVing the two species. Soine- 

 tliing similar applies to /*. Ininvaliiin Lemni. fl909 p. 189). 



Phormidium Corium Ag.i (ioni. 



Cioniont, Monoer. II |). 172, pi. V, lig. 1—2. 



X. Icel. Hrafnagil, hot sjjrings ^^/s 1890 Hj. J.)! — \V. 

 Joel. Stiirlurcykir; siliceoiis sinter at hot spiing ^/s 1914. 

 — S. Icel. Geysir. Hlesi; margin of the hot basin Stp.)I 

 "Laiigarvas". Ncar the margin of northern s|)ring, temp. 

 = 100" C. ,Slp.)! Reykjavik, Laugarne iStp. ! Mun^arbak, 

 '-/9 1897 (H. J.)! 



Area: Eiir., Afr., Am., Austr., Lappland, Alaska, Greenland. 



Strangely enough this species is found in Iceland almost exclii- 

 sively at the hot springs, hardly in the hot water, but rather on the 

 margin of the spring. Otherwise the species is found on stones in 

 streams, on moist trunks and thatched roofs. Thercfore it is not ijuite 

 correct when Coupin il915 p. 57) refers it to the species which are 

 found exclusively in rapidly running water. However, Ihere is a possi- 

 bility that the species might be divided in various si)ecies. 



The Icelandic specimens correspond rather closely to Gomont's dc- 

 scription and ligures. The apical cell, however, is as a rule longer than 

 that Jigurcd by Gomont. Almost identical apical cells are, nevertheless, 

 found in a sample in Herb. Lyngbye, determined by Gomont. 'Iherefore, 

 I have not hesitated in referring the specimens in question to Phormi- 

 dium Corium in spite of the slight deviation. 



Phormidium subcapitatum Boye P. n. sp. 



Ph. strato membranaceo, atro-æruginco, trichomatibus llexuoso-cur- 

 vatis, sæpe parallclis, læte ærugineis, 1.8—2.2 // crassis ad genicula leviter 

 constrictis, apice rectis. inlerdum attenuatis, 

 subcapitatis; arliculis diametro aniualibus vel 

 ad 3-plo longioribus, intcrdum granulis spar- 

 sis farctis; cellula apicali calyptram rotun- 

 datam vel depresso conicam jiræbentc; va- 

 ginis mucosis, chlorozincico jodurato non 

 coerulescentibus. 



a 



Y-- 



\V. Icel. Geitaberg. In soil in a potato 

 field just in front of the house ^/s 1914. 



Fig. 5. 

 Phormidium siihcapilutitm n sp. 

 DifltTcnt forms of apices. 

 (Xl'iUO). 



This species is one of the thinnest in which a calyptra is found. 

 In order to see it the finest Optical facililies are needed. The sj)ccies, 

 to which it is most closely related. is apparently P. iifricdiiiim Lem- 

 mermann 1911 p. 89j. This species, however, has slightly thiiiner tri- 

 chomes and its vaginæ colour with chlor-zinc-iodine; and, when it fur- 

 thermore is taken into consideration that P. alricanum was found in a 

 hot spring in Central-Africa. I think it justinal)le to set iip /', subcapita- 

 tum as a new sjiecies. 



