THE BRYOPHYTA OF ICELAND 



511 



leaf-margin is almost straight in outline, while in L. decipiens it is dis- 

 tinctly concave, as in L. filamentosa. 



The variety grew abundantly on somewhat damp rocks; it is some- 

 what coarser and less branched than the type which it resembles ex- 

 actly in leaf-form and size of the cells. The leaf-cells in this form are 

 so highly thickened and porous that the walls almost appear like a 

 string of beads and are often broader than the cell-space. 



Fig. 13. a. Leaves of Lescurcea Breidlcri (X 20): b. leaves of L. radicosa (X 20); 

 c. leaves of L. decipiens (X 20); d. leaves of L. decipiens v. crassirete (X 20): c, leaf- 

 cells of L. decipiens (X 320): /. leaf-cells of /.. decipiens v. crassirete (X 320). 



225. Lescuraea radicosa (Mitt.) Hagen. 



Lescurcea riyescens (\Vils.) Br. eur.; Pseudoleskea radicosa (Mitt.) Lindb. 



Ptychodium Pf undine ri Limpr. 



N. Iceland: Oxnadalur, Tvera!; sterile. 



In the above locality it grew scantily on a stone by the river. 



226. Lescuraea filamentosa (Dicks.) Lindb. 



Psendoleskea atrovirens DicksJ Br. eur. 

 Widely distributed. 



