THE AERIAL ALGÆ OF ICELAXD 



385 



Caloneis silicula Ehrb. var. genuina Cl. Cleve Syn. I, p. 51. V. H. 

 Syn. PI. XII, fi^. 18. 



E. Icel. 15 - N. Icel. 140. 



This highly variable species 1 have only found in few specimens on 

 a wall among Prasiola and in a ditch among desiccated algæ. As it be- 

 longs to the species comnion in Iceland (Østruj) 151 samples), it must 

 be taken for granted that it is no aérial Diatom. 



var. gibberula Kiitz. Cl. Svn. I, p. 51. Nav. limosa v. gibbe- 



rula V. H. Syn, PI. XII, lig. 19. 



E. Icel. 85. 



Like the preceding one this variety is hardly an aerial form. 



— — var. minuta Griin. Cl. Svn. I, p. 52. N. ventricosa v. minuta 

 V. H. Syn. PI. XII, lig. 26. 



E. Icel. 125 — N. Icel. 169. 



As regards life conditions this variety probably behaves like the 

 other forms of the species. Østrup presumably did not distinguish 

 between the various varieties of the species but groups them together. 



Caloneis Vaucheriæ Boye P. n. sp. 



Caloneis valva lanceolata, apicibus protractis, long. 18 /^ 

 lat. 4—4,4//, striis 23 in 10//, radiantibus vel ad apices pa- 

 rallelis. Area apicali angusta; area centrali in fasciam trans- 

 apicalem dilatata. Fig. 11. 



N. Icel. L. 218 — W. Icel. 336, L. 338 — S. Icel. 386. 



Fig. 11. 



Cdloiwis 



Vdiicheriæ. 



For the present I refer this small species to Cdloncis, 

 since I think I have seen a fine apical line on either side 

 a little way inside the margin. In girdle view the frustule Boye P. n. sp. 

 is rectangular, and the terminal nodules are somewhat re- '^'^ 1-00). 

 moved from the apices. 



Only found on the ground. Two of the samples were from very 

 damp soil, one from a potato field and one from a road. It is undoubt- 

 edly a genuine aerial species, though perhaps it will not withstand much 

 desiccation. In two of the samples it was found among Yaiicheria. 



Anomoeoneis Plitzer. 



Anomoeoneis brachysira (Brcb.) Grun. Cl. Syn. II, p. 7. Xavicula 

 serians v. minima V. M. Syn. PI. 12, lig. 8, 9. 



E. Icel. 4, 123, L. 125 — N. Icel. 256 - W. Icel. 298 — S. Icel. 295. 



In the main probably an alpine-arctic species (ep. Stockmayer 

 1909, p. 82 f.) rarely occurring in great quantily. According to tiie data 

 (Østrup 8 samples, ego 5 samples) it would seem to be predominantly 

 aérial in Iceland. The reason why I only found it with cell conlcnts in 

 one sample is probably that there was only a small nuniber of speci- 



