ISOTHECII. 113 



Dioicous ; forming soft, silky, yellow-green patches. Stem 

 creeping ; branches short, crowded, erect, often curved ; leaves 

 erecto-patent, sometimes stibsecund, ovato-lanceolate, strongly 

 acuminate, plicate, very minutely toothed; cells narrow, but 

 slightly altered at the base ; fruitstalk rough, about an inch 

 long, reddish; sporangium ovato- cylindrical, symmetrical, 

 erect ; lid conical, gradually attenuated into a short beak ; 

 intermediate cilia absent. 



18. ORTHOTHECIUM, Schimp. 



Sporangium erect, symmetrical; ring broad, dehiscent; 

 veil small ; peristome double ; teeth of inner peristome as long 

 t as those of the outer; intermediate cilia wanting or rudimen- 

 tary ; leaf- cells narrow, not quadrate at the angles. 



1. O. rufescens, Schimp.; stem erect, tufted; branches 

 erect, slightly compressed; leaves erecto-patent, lanceolate, 

 strongly acuminate, plicate, entire, nerveless ; sporangium ob- 

 long ; lid conical, acuminate. Hook. Wih. t. xxvi. ; Eng. 

 Bot. t. 2296 ; (Moug. % Nest. n. 514.) 



On moist shady rocks near waterfalls, in alpine and espe- 

 cially calcareous districts. Bearing fruit in summer. 



Dioicous ; forming silky, soft, rufous tufts. Stem 2 or 3 

 inches high, erect or sometimes procumbent, dichotomously 

 branched ; branches erect, fastigiate, with sometimes a few 

 branchlets ; leaves crowded, erecto-patent, lanceolate, strongly 

 acuminate, repeatedly sulcate, entire, nerveless; cells ex- 

 tremely narrow even to the base, not enlarged at the angles ; 

 fruitstalk even, 1-2 inches long ; sporangium oblong, erect, or 

 very slightly inclined ; lid conical, short, acute ; inner peri- 

 stome with short intermediate cilia. 



2. O. intricatum, Schimp. ; stem prostrate, branched ; 

 branches erect; leaves lanceolate, acuminate, erecto-patent, 



