PLEUROCLADA. 195 



coniiivent ; texture somewhat thick, cells 4 -, 5-, and G-sided, 

 smallish, walls thick, no trigones or thickened angles. Stipules 

 large, as long as the leaves, ovate-lanceolate, entire. Flowers ? 

 terminal on long branches. Bracts oblong or oblong-ovate, bifid 

 to below the middle, segments lanceolate-acuminate, entire ; bract- 

 eole free or adnate to one of the bracts, much smaller than the 

 bracts, oblong-ovate or ovate, retuse, emarginate or entire ; sub- 

 bracts similar to the innermost, only smaller. Perianth projecting 

 much beyond the bracts, linear or narrowly fusiform, cylindrical 

 below, above deeply 4-5-plicate, folds obtuse, composed of a single 

 layer of cells, near the middle about 80 cells round, mouth con- 

 stricted, irregularly and slightly dentate. Oalyptra delicate, 

 composed of a single layer of cells. Fruit and male stems not 

 yet known. 



Dimensions. — Stems |^ to 1 inch long, diam. '175 to "1 mm., 

 with leaves '5 to "75 mm. wide ; leaves "3 mm. x '25 mm., segments 

 •125 mm., -275 mm. x '25 mm., seg. "125 mm., -25 mm. x "225 mm., 

 seg. '15 mm., '4 mm. x '3 mm., seg. "225 mm. ; cells "02 mm. x 

 "025 mm., -0225 mm. x '0225 mm., '03 mm. x -025 mm., '02 mm. 

 X "02 mm.; stipules -3 mm. x '125 mm., "35 mnrx"15 mm., 

 '25 mm. x "l mm., "275 mm. x *15 mm. ; sub-bracts '75 mm. x 

 '5 mm., sea:. '4 mm., "9 mm. x '45 mm , seg. *55 mm. ; bracts 

 1' mm. X '6 mm., seg. '6 mm. ; perianth 2' mm. x '5 mm., teeth 

 at the mouth "04 mm. 



Hab. — Moist rocks or earth in alpine situations. Extremely 

 rare. 15. Loch-na-gar, Aberdeenshire, /. Sim, April 1878. 



Found in Iceland, Northern Europe and Greenland. 



Obs. — Differs from P. albescens (Hook.) in the more slender 

 habit of the plant, closer, more erect leaves, which are usually 

 narrower, with deeper sinus, much less concave, not hemispherical, 

 but simply complicate-concave, stipules narrower with no basal 

 tooth or teeth, bracts longer and narrower, deeply bifid to below 

 the middle, segments lanceolate-acuminate, not to a thirti, with 

 seirments subacuminate-acute, bracteole retuse, emarginate or 

 entire, with no basal teeth, perianth narrower, more plicate near 

 the apex, composed of a single layer of cells, not several. Con- 



