Didymodon.} MUSCI-ACROCARP1-PERISTOMI. 81 



elongated csespitose, leaves nearly distichous subulato-seta- 

 ceous, capsule erect ovato-cylindraceous, lid conical. Schrad. 

 Spicil. p. 64. Drum. Muse. Scot. v. 1. n. 52. Muse. Brit. ed. 2. 

 p. 119. t. 20.— Sivartzia capill. Hediv. St. Or. v. 2. t. 26.— 

 Cynontodium capill. Hediv. Sp. Muse. — Trichostomum capill. 

 FL Brit. p. 1236. E. Bot. t. 1152. — Bryum capill. Dicks. — 

 (3. ithyphylla ; smaller, leaves shorter rigid more distichous. 

 D. subulatum, Schkuhr, Deutschl. Moose, p. 65. t. 28. 



Banks and rocks in alpine situations; upon walls about Blair in 

 Athol. Fr. Spring. 



12. D. longirostris ? Web. et Mohr, (long-beahed Didy- 

 modon); stems elongated loosely csespitose, leaves subulato- 

 setaceous falcato-secund, seta incurved flexuose, capsule oblongo- 

 cylindrical, lid rostrate. Fl. Cr. Germ. p. 156, and 463. — Cyno- 

 dontium longirostre, Schwaegr. Suppl. v. I. p. 211. t. 29. 



Moist shady rocks in alpine situations, but always barren ; as on 

 Ben-y-Gloe and Cairngorum. Fr. — I introduce this plant with much 

 hesitation under the above name ; because though the stems and foliage 

 entirely accord with those of authentic specimens of D. longirostris ; yet 

 the most important characters depend upon the fructification, which 

 I have never seen on British individuals. 



13. D. keteromdllus, Hook, and Taylor, (curve-leaved Grimmia); 

 stems rather short, leaves subsecund subulate, capsule ovato- 

 cylindraceous, lid conical. Muse. Brit. ed. 2. p. 119. Drum. 

 Muse. Scot. v. 1. n. 51. — Weissia heterom. Hediv. St. Cr. v. 1. 

 t. 8. — Grimmia heterom. Fl. Brit. p. 1194. E. Bot. t. 1899. 

 Turn. Muse. Hib. p. 30. — (3. leaves more falcato-secund. D. 

 ho?nomallus, Hediv. Sp. Muse. t. 23. /. 1 — 7. — Grimmia homo- 

 ?nalla, Fl. Brit. p. 1194. E. Bot. t. 1900 — Bryum Weissia, 

 Dicks. 



On the earth, especially in mountainous districts. Fr. Summer. — 

 The reasons for considering the Weissia homomalla, Hedw. to be the 

 same as our Didym. heteromallus, are given in the Muse. Brit. This 

 species is remarkable for its crowded mode of growth, yellowish leaves, 

 pale fruit-stalks, which latter become redder upwards, especially as the 

 plant advances to maturity. 



14. D. pusillus, Hedw. {dwarf Didymodon); stems dender 

 elongated, leaves erect rigid from a broad lanceolate base subu- 

 late, capsule erect oblong, lid obliquely rostrate. Hedw, Sp. 

 Muse. p. 104. Web. et Mohr, Fl. Cr. Germ, p. 157. — Trichos- 

 tomum pusUlum, Hedw. St. Cr. v. 1. t. 28. E. Bot. t. 2380.— 

 Bryvui pusillum, Dicks* 



"Sandy ground," Mr. Dickson, in E. Bot. Bank (since destroyed) 

 three miles from Belfast, on the Dublin road; and in the garden of 

 J. Templeton, Esq. near Belfast, Mr* DrumtncmtL Fr. Spring. — The 

 short upright rather rigid leaves, with their broad ami lanceolate base, 

 distinguish the present Bpeciea from the preceding, than which it is 

 much smaller. NO certain station had been known of thia rare plant, 

 in Britain, till Mr. Drummond gathered the .specimen^ now lie fore us 

 in Ireland. 



