18 MUSCI. [Didymodon. 



On the cliffs of Killiney Bay, near Dublin : very rare. The cap- 

 sule at length appears inclined from the bending of the top of the seta. 

 This is a gregarious, very minute species. 



4. D. Brioitoni, Arnott. Stems tufted ; leaves lanceolato- 

 subulate, their margins slightly recurved, subserrulate, twisted 

 when dry ; capsule ovate ; lid shortly rostrate. Arnott Disp. 

 Masc. p. 36. Muse. Brit. eel. 2, p. 117. Supp. t. \. D. obscurus, 

 Kaulfuss in Sturm. Schwaegr. Supp. 2, p. 80, t. 125. Grev. 

 FL Cr. t. 193. 



Rocks at Powersconrt Waterfall. I submit to the authority of the 

 above-quoted able botanists in arranging this plant under Didymodon. 

 Yet the peristome consists of 16 teeth, united at the base, split into 

 unequal segments, the section not continued down to the bottom of 

 each tooth, but only marked there with a dark line ; sometimes they 

 are entire or perforated. The peristome is very short, and when the 

 lid is first removed lying across the mouth of the capsule. In the 

 first edition of Muse. Brit, it is justly remarked, " the teeth of the 

 peristome will be found to be irregularly divided." 



5. D. rigidulus, Hedw. Leaves imbricated, lanceolate, cari- 

 nate, much acuminated, their margins reflexed, entire, their 

 nerve rigid, excurrent ; capsule oblongo-ovate, erect ; lid ros- 

 trate. Hedw. St. Cr. v. 3, t. 4. Muse. Brit. ed. 2, p. 11 7, t. 20. 



On large stones and walls. The variety with cylindraceous capsules, 

 observed by Mr. Wilson, near Beaumaris, likewise is found at Dunker- 

 ron. Upon removing the lids carefully, the teeth of the peristome are 

 found slightly twisted at the top, which supports Mr. Turner's observa- 

 tion of an analogy with the genus Tortula. 



6. D. irifarium, Swartz. Leaves rather distant, lanceolate, 

 rather obtuse, carinate, their nerve scarcely percurrent; capsule 

 oblongo-ovate, erect; lid rostrate. Swartz. Masc. Suec. p. 28. 

 Muse. Brit. ed. 2, p. 118, t. 20. 



On wet banks. The peristome of at least the small variety, first 

 found by Mr. James Drummond, near Cork, has 16 equidistant teeth, 

 united at the base, each marked with a longitudinal dark line, sometimes 

 split or perforate, sometimes entire. It is probably distinct. 



7. D. crispulus, Hook. Stems tufted ; leaves erect, lanceo- 

 lato-subulate, entire, their margins slightly incurved, concave, 

 their nerve excurrent, indexed at the summit ; capsule oblongo- 

 ovate, erect; lid rostrate. Hook. Eng. Fl. v. 5, part 1, p. 30. 



On Dunkerron castle, County of Kerry, and on limestone near the 

 sea. The generic character is obscure. The leaves twisted when dry. 



8. D. bracJiydontius, Hook. Leaves widely spreading, linear, 

 entire, rather obtuse ; their nerve excurrent and slightly re- 

 curved towards the summit, twisted when dry; capsule oblongo- 

 ovate ; lid rostrate. Hook. Eng. Fl. v. 5, part 1, p. 30. 



Maritime banks, at the Sound, near Kenmare : barren. There is an 

 apophysis at the base of capsule. 



9. D. capillaceus, Schrad. Stems elongated ; loosely cces- 



