.] GYMNOSTOMI. 15 



S. palustre, ft. Linn. Dill Muse. t. 32. f. 2. A. 

 HAB. Bogs, extremely common. 

 4. S. cuspidatum; branches attenuated, leaves lanceolato-subu- 



late lax. (TAB. IV.) 



Sphagnum cuspidatum. Ehrh. Crypt, n. 25. ("according to Smith. ) 



Smith, Fl. Brit. p. 1147. Engl. Sot. t. 2392. Schwaegr. Suppl. v. 1. 



p. 16. t. 6. Turn. Muse. Hib. p. 6. Moug. et Nestl. n. 405. Hobson, 



Brit. Mosses, v. 2. n. 3. Funck, Deutschl. Moose, t. 3. n. 7. Drum- 



mond, Muse. Scot. v. 1. n. 2. Hook. Fl. Scot. P. 11. p. 121. Nees et 



Hornsch. Bryol. Germ. v. 1. p. 23. t. 4./ 9. Am. Disp. Muse. p. 6. 



Dill. Muse. t. 32. f. 2. B. 



HAB. Bogs, not uncommon, generally found growing en- 

 tirely under water ; rare in fruit. 



In this, as well as in the foregoing species, there are varieties 

 with more or less squarrose leaves. 



The difficulty of detecting this plant in fructification, joined 

 to its being usually found wholly immersed in water, affords a 

 strong reason for considering this as a mere variety of S. acuti- 

 folium, arising from situation. Even in the same plant the 

 leaves are found to vary; the lower leaves upon the branch 

 being often shorter and broader, and the upper ones more 

 lengthened and narrow. Specimens of this plant, four feet 

 long and with the leaves three-fourths of an inch in length, 

 have been found by Dr. Greville ; but in this state it never 

 bears fruit. 



The Sphagnum simplicissimum, (Bridel Meth. p. 3.J Mr. 

 Arnott suspects to be an Orthotrichum. 



IV. GYMNOSTOMUM. 



GEN. CHAR. Fruitstalk terminal; mouth of the capsule naked, 

 or at most, in an early stage, closed with a more or less 

 completely formed horizontal membrane; Calyptra di- 

 midiate. (TAB. I.) 



We noticed in the first edition of this work, published in 1819, 

 the presence of a delicate, horizontal, annular membrane in the 

 mouth of the capsule of some of the Gymnostoma, when examined 



