Tetraphis.] APLOPERISTOMI. 33 



(even more so than in Schistostega), and the teeth of the peri- 

 stome are reticulated, not striated as those of other Mosses. 

 The Calyptra is striated or furrowed. 



Our Teiraphis Broioniana, together with two nearly allied 

 species, have lately been separated from the genus by Dr. Schwae- 

 grichen under the name of Tetrodontium, with the following 

 character: " Peristomum simplex: dentibus quatuor triangulari- 

 bus. Flores dioeci, gemmiformes. Calyptra plicata." 



1. T. pellucida ; stems elongated, leaves ovato-acuminate, those 



of the perichsetium lanceolate, capsule cylindrical. (TAB. 

 VIII.) 



Tetraphis pellucida. Hedw. Sp. Muse. t. 7. f. 1. Engl Bot. t. 

 1020. Smith, Fl. Brit. p. 1179. Schwaegr. Suppl v. 1. p. 39. Brid. 

 Meth. p. 26. Hook. Fl. Scot. P. II. p. 124. Moug. et Nestl n. 14. 

 Hobson, Brit. Mosses, v. 1. p. 8. Am. Disp. Mtisc. p. 14. Hook, in 

 Fl. Lond. cum Ic. (new series}. 



Tetraphis cylindrica. Punch, Deutschl. Moose, t. 6. n. 3. 



Mnium pellucidum. Linn DM. Muse. t. 31. / 2. 



HAB. Generally found on decaying trunks of trees ; some- 

 times on the ground. 



This plant has a peculiar character which distinguishes it 

 from every known moss. The leaves are of a pale and pleasant 

 green colour, rigid, furnished with a nerve which terminates 

 below the point ; those surrounding the perichsetium are much 

 longer and narrower than the rest. Capsule oblong, cylindri- 

 cal ; teeth large, very conspicuous, brown ; calyptra much re- 

 sembling that of an Orthotrichwn, but glabrous. Besides the 

 plants which bear the male and female fructification, (usually so 

 called), there are others which are terminated by cup-shaped 

 receptacles, consisting of broadly obcordate leaves, in the centre 

 of which are fixed, by a short footstalk, small spherical 

 bodies, bearing an exact analogy to the anthers of Jungerman- 

 nice, 



2. T. Browniana ; stems very short, leaves few linear slightly 



incrassated upwards, those of the perichaetium ovate obtuse, 

 capsule ovate. (TAB. VIII.) 



Tetraphis Browniana. Grev. FL Edin. p. 230. Drummond, Muse. 

 Scot. v. 2. n. 13. Grev. Scot. Cr. Fl. t. 169. Am. Di#p. Muse. p. 14<. 



Tetrodontium Brownianum. Schwaegr. Suppl. v. 2. t. 129. 

 C 



