Didymodon] MUSCI. 17 



of the plant, and its companulate calyptra, cause it properly to rank 

 under Grimmia, and it is nearly allied to the following. 



5. G. tricophylla, GREV. Stems elongated, loosely tufted ; 

 leaves waved, lanceolate, gradually tapering into a diaphonous, 

 subserrulate point ; seta curved, capsule ovate, striated ; lid 

 conical, acuminate, somewhat oblique. Grev. Fl. Cr. t. 100. 

 Muse. Brit. ed. 2, p. 68. Supp. t. 2. 



Near Dublin, Dr. Scott and Dr. Stokes. A barren plant occurs 

 at the Aooreagh river, County of Kerry, on rocks, that, for the pre- 

 sent, I must consider only a variety of this species. It is more closely 

 tufted ; all the shoots are black except their conspicuous hair points, 

 that cause it to appear very hoary ; by drying it is more harsh and 

 brittle than the plant described, which has the younger shoots of a pale 

 yellowish-green colour. The calyptra is split, particularly on the side 

 to which the lid inclines. 



6. G. spiralis, HOOK, et TAYLOR. Stems elongated, tufted ; 

 leaves lanceolate, tapering into a diaphanous point, spirally 

 twisted about the stem when dry ; seta curved ; capsule ovate, 

 smooth. Muse. Brit. ed. 2, p. 69. Supp. t. 2. 



On Slemish mountain, County of Antrim, Mr. Templeton. 



7. G. torta, HORNSCH. and NEES. Stems densely pulrinate ; 

 leaves lanceolate, acuminate, the upper subpiliferous, spirally 

 twisted when dry. Bryol. Germ. p. 1 72, t. 22, /. 24. Muse. 

 Brit. ed. 2, p. 70. Supp. t. 2. 



Cliffs on Mangerton, county Kerry. 



14. DIDYMODON. Hedw. 



Seta terminal. Peristome single of 16 or 32 teeth, approached 

 in pairs, or united at the base* Caljptra dimidiate. 



1. D. purpureus, HOOK, et TAYLOR. Leaves lanceolate, acu- 

 minate, their margins recurved, entire ; capsule ovato-cylindra- 

 ceous, oblique, substrumose at the base, striated when dry ; lid 

 conical. Muse. Brit. ed. 1, p. 65 ; ed. 2, p. 113, t. 20. Dicr. 

 purpureum, Hedw. Sp. Muse. t. 36. 



On banks and walls, very common. This is not much allied in habit 

 with the other species of Didymodon, and perhaps the union of the 

 approximated pairs of teeth by transverse processes would justify its 

 separation. 



2. D. inclinatus, SWARTZ. Leaves distichous, with a lance- 

 olate sheathing, base setaceous; capsule ovate, inclined, smooth; 

 lid conical. Swartz. Muse. Sues. p. 28. Muse. Brit. ed. 2, p. 

 114, t. 20. 



On the mountains of Cunnamara, Mr. J. T. Mackay, very rare. 



3. D. nervosus, HOOK, et TAYLOR. Leaves obovate, apicu- 

 late, their nerve excurrent, thickened above ; capsule ovate ; 

 lid shortly rostrate. Muse. Brit. ed. 1, p. 66; ed. 2, p. 115, t. 

 20. 



