4S APLOPERISTOMI. \_Polytrichum. 



equidistant teeth, all united at their summit ; Calyptra 

 dimidiate. (TAB. I.) 



This curious genus, which was first established by Swartz in 

 Schrader's Journal, approaches in habit, as Walilenberg justly 

 observes, to Bartramia fontana, and the exotic species, named C. 

 australe, has actually been described by Bridel under the name of 

 Bartramia pentasticha. 



1. C.boreale; stems elongated, leaves lanceolate acuminate cari- 

 nate slightly toothed. (TAB. X.) 



Conostomum boreale. Swartz in Schrad. Sot. v. 1. p. 24. t. 5. 

 Schwaegr. Suppl v. I. p. 79. t. 21. Brid. Meth. p. 27. Hobson, Brit. 

 Mosses, v. 2. n. 12. Drummond, Muse. Scot. v. 1. n. 71. Hook. FL 

 Scot. P. II. p. 125. Am. Disp. Muse. p. 40. 



Grimmia Conostoma. Smith, Fl. Brit. p. 1196. Engl Bot. t. 1135. 

 Bryum tetragonum. Dicks. Crypt. Fasc. 2. p. 8. t. 4. f. 9. 

 HAB. Summits of the Scotch mountains, not unfrequent. 

 This is altogether an alpine plant, rarely, perhaps, in our 

 country, found at a lower degree of elevation than 3000 feet 

 above the level of the sea. In Switzerland its place of growth 

 is at a height of 7 or 8000 feet upon the mountains. Upon 

 Goat-fell, in Arran, we have gathered this plant four or five 

 inches in length, but always barren. 



The leaves do not appear to us, by any means, to give the 

 stems a regularly tetragonous appearance, as Mr. Dickson's 

 name implies, nor to be quinquefarious, according to Sir James 

 Smith's remarks. Sometimes, in dried specimens, the imbrica- 

 tion of the carinated leaves makes the stems seem angular ; but 

 when moist, that appearance vanishes, and they are nearly cy- 

 lindrical. The capsules, and indeed the whole plant, bear no 

 very slight resemblance to small specimens of Bartramia fon- 

 tana ; the operculum, however, is conico-subulate. 



XI. POLYTRICHUM. 



GEN. CHAR, fruitstalks terminal; Peristome single, of 32 

 or 64<, equidistant, incurved teeth ; their summits united 



