Splachnum.] A P L O P E R I S T O M I. 35 



given to this species by Mr. Dickson, in honour of its first dis- 

 ^eoverer, the greatest Botanist of this or any other age. 

 Still another Tetraphis, allied to the two in question, is the 

 T. repanda of Funck, which has creeping roots and numerous, 

 usually simple, erect, filiform, surculi, covered with oblongo- 

 linear, nerveless, membranaceous leaves, very different from 

 those of the perichcetium, and still more unlike those of our T. 

 Browniana. 



Dr. Schwaegrichen has recently published our T. Browniana 

 as a species peculiar to Britain. 



IX. SPLACHNUM. 



GEN. CHAR. Fruitstalks terminal ; Peristome single, of eight 

 double teeth ; Capsule with an evident apophysis ; Ca- 

 lyptra mitriform, glabrous, without furrows. (TAB. I.) 



Although in characters it may be difficult to distinguish this 

 genus from Orthotrichum, (since there is scarcely one of the above 

 mentioned marks which may not be found to exist, in a greater or 

 less degree, in some species of the latter genus,) yet, in general 

 habit, as well as in their places of growth, they are abundantly 

 distinct. The Calyptra which Mohr denominates mitriform, ap- 

 proaches, in this genus, nearer to what is termed dimidiate, and 

 is totally different from that of Orthotrichum, which, (besides that 

 from its greater size it may be found remaining upon the fully 

 formed capsule,) is, moreover, generally deeply furrowed, and we 

 may add in almost every instance, beset with hair-like bodies. 

 Gymnostomum Griffithianum, and Weissia splachnoides bear a 

 great resemblance to this genus ; but in the former the mouth of 

 the capsule is destitute of true peristome, and in the latter it is 



Strasburg," he says, " 1 lately SRAV a letter from a German Botanist who has 

 studied the Tetr aphis ovata with great attention, and states, that when it grows 

 upon sandstone rocks, the linear radical leaves are often found ; upon rocks of 

 granite, they are found only here and there and with great difficulty." Hence, 

 he is disposed to unite the T. ovata with our T. Browniana. 



C2 



