30 MUSCI-ACROCARPI-PERISTOMI. [Didymodon. 



8. D. trifdrius, Sw. (three-ranked Didymodon); leaves rather 

 distant somewhat trifarious lanceolate obtuse carinate with the 

 nerve scarcely reaching to the point, capsule oblongo-ovate 

 erect, lid rostrate. Muse. Suec. p. 28. Drum. Muse. Scot. v. 2. 

 n. 48. Muse. Brit. ed. 2. p. 118. t. 20. — Swartzia trifaria, 

 Hedw. St. Cr. v. 2. t. 28. — Cynontodium trif avium, Hedw. Sp. 

 Muse. — Trichostomuni trifarium,Fl. Brit. p. 1236. B.Bot. t. 1707. 

 — T. linoides, Fl. Brit. p. 1247. E. Bot. t. 2298i (?iot of Dicks.) 

 Dill. Muse. t. 47. /. 39. (according to Mr. Oglander). 



On moist banks. Fr. Dec. and Jan. — This, it must be confessed, is 

 very nearly allied to the last, and I have seen some plants so inter- 

 mediate that I cannot pronounce with certainty upon them. It is best 

 known by its shorter, more patent, far less rigid, more obtuse, more 

 distantly placed and somewhat trifarious leaves. 



9. D. crispulus, (obscure Didymodon); stems short scarcely 

 branched, leaves erect lanceolato-subulate with entire and 

 slightly incurved margins channelled above concave and rounded 

 at the summit, nerve suddenly inflexed towards the apex and 

 excurrent, capsule oblongo-ovate erect, lid rostrate. Wils. — 

 Trichostomuni crispulum, Bruch, in Un. It. — Didymodon recon- 

 ditum, Wils. Mss. 



On maritime limestone rocks near Carneg Onnen and Tros-y-Marian, 

 Anglesea; and upon Ormeshead, Caernarvonshire, Mr. W. Wilson. Fr. 

 May and June. — Leaves brownish, widest at the base, tapering upwards; 

 nerve reddish and opaque. Wils. 



10. D. brachydontius, Wils. Mss. (sharp-toothed Didymodon); 

 stems short scarcely branched, leaves widely spreading linear 

 with plane margins bluntish entire, the nerve excurrent and 

 slightly recurved towards the apex, capsule oblong-ovate, lid 

 rostrate, peristome very short. Wils. — Trichostomuni brachy- 

 dontium, Bruch, in Un. It. 



On maritime limestone rocks, near Carneg Onnen, and Tros-y-Marian, 

 Anglesea ; and upon Ormeshead, Caernarvonshire ; Mr. W. Wilson. 

 Fr. June. — " Stems erect, tufted, branched, about an inch long. 

 Leaves much spreading when wet, slightly inflexed and contorted when 

 dry, lanceolato-oblong, blunt, with a strong and considerably excurrent 

 nerve, which is rather pellucid when the leaf is placed sideways under 

 the lens ; margin plane, entire ; nerve of uniform colour with the sub- 

 stance of the leaf, which is composed of very minute cellules, of a lively 

 green colour. Capsule ovato-oblong. Fruitstalk pale green. 



The widely spreading, bright green, apiculate leaves and their closer 

 texture ; the broader capsule, pale fruitstalk, and the narrow appearance 

 of the base of the leaf when dry, will serve to distinguish this from 

 the D. crispidus, without inspection of the peristome, which it is very 

 difficult to find. The broader blunt leaves and the excurrent nerve, 

 with the pale white peristome, and perhaps the shortness of the lid suffice 

 to keep it distinct from W. tenuirostris; and probably the flaccid spreading 

 stems, lax acuminated leaves, red somewhat torulose teeth of W. tenui- 

 rostris, may furnish additional characters. It is nearly allied to Trichos- 

 tomum Jlexisetum of Bruch." Wils. 



11. D. capilldceus, Schrad. (fine-leaved Didymodon); stems 



