Polytrichum.] MUSCI. 27 



subulate, entire, their margins recurved ; capsule cylindraceous, 

 somewhat narrower at the mouth ; lid elongato-conical. 



On wet sand on the banks of the Dargle river, County Wicklow. 

 Stems 1 2 inches high ; branched, loosely tufted. Leaves long, 

 acuminated, but without any excurrent point, of a light yellowish 

 green, much crisped and twisted when dry. Seta one inch or more 

 high, very slender, flexuose, reddish below, of a light yellowish-green 

 while the capsule is yet young. Capsule slightly ovato-cylindraceous, 

 very smooth, erect, its mouth narrow. Lid near the mouth of the 

 capsule contracts and rises up as an acuminated cone. Calyptra 

 dimidiate. Peristome of 32 filiform teeth united in pairs (more rarely 

 three together) by transverse processes ; at their summits they are 

 slightly spirally twisted. The lid, as in Tortula, exhibits spiral stria 

 externally. The peristome is short and very pale, as observed in the 

 Z. leucostoma described by Mr. Brown under the name of Barbula 

 leucostoma. I have another species from Madeira. 



20. CINCLIDOTUS, Beauvois. 



Seta terminal. Peristome single, of 32 filiform spirally twisted 

 teeth, anastomosing at the base, and fixed by their tops to the 

 summit of the columella. Calyptra campanulate. 



The lid may be observed to be spirally striated externally, which 

 is an excellent indication of the twisting of the teeth, although this 

 is by no means so remarkable as in most of the Tortula. 



1. C. fontinaloides, Beauv. Prodr. p. 28 and 32. Muse. Brit, 

 ed. 2, p. 51, t. 11. 



On stones or stems of trees, occasionally inundated by running 

 water. Several capsules occurring along a principal stem, the fructi- 

 fication might be supposed to be lateral ; but it appears really to be 

 fixed on the tops of very short branches. The lid is conico-acuminate. 



21. POLYTRICHUM, Linn. 



Seta terminal. Peristome single of 32 or 64 short equidistant 

 teeth, their summits united by a flat membrane. Calyptra 

 dimidiate, small. 



The teeth are not transversely striated as in other genera. 



1. P. undulatum, HEDW. Leaves thin, lanceolate, their mar- 

 gins plane, waved, denticulate; their nerve winged; capsule 

 cylindraceous, curved ; lid subulate. Hedw. St. Cr. v. 1, t. 16, 

 17. Muse. Brit. ed. 2, p. 43, t. 10. 



On banks and in woods ; frequent. The leaves are less rigid than 

 in the congeners. A most remarkable variety occurs at the Dargle 

 river, with the leaves much crisped when dry, the seta not exserted out 

 of the perichaetial leaves, the capsule very short, nearly erect and 

 turbinate ; the calyptra remaining fixed below the capsule after the 

 falling of the lid, as sometimes occurs in Timmia, 



2. P. piliferum, SCHREBER. Leaves lanceolate-subulate, their 

 margins involute, entire, terminating in a diaphanous hair-like 

 point : capsule ovate, obtusely quadrangular, furnished with an 

 apophysis ; lid conical. Schreb. Fl. Lips. p. 74. Muse. Brit. ed. 

 2, p. 44, t. 10. 



