294 musci prjEteriti. 



which was one of the first things I had compared with H. Borrer- 

 ianum in 1846 ; and my original note on it is still in its proper 

 place. The two seemed so plainly distinct that I had dismissed all 

 thought of their possible identity. Wilson, however, assured me 

 that Miss Hutchins's specimens were exactly intermediate between 

 mine and those of Menzies ; and, bowing to his decision (though 

 unconvinced), I quashed my description and diagnostic notes and 

 published the moss as " H. elegans, Hook.," ignoring even any 

 mention of H. Borrerianum. But when, many years afterwards, 

 I came to see Wilson's figure and description of his " H. elegans " 

 in ' Bryol. Brit.," it was plain to me that if they correctly repre- 

 sented Miss Hutchins's plant (as was to be supposed), they also 

 agreed exactly enough with my H. Borrerianum, but by no means 

 with the true H. elegam of Hooker. The recent acquisition, 

 through the liberality of Messrs. Whitehead, Ashton, and Pearson, 

 of Welsh specimens in good fruit of H. Borrerianum, has enabled 

 me to institute a more rigorous comparison between the two, and 

 to prove them specifically distinct. 



Plagiothecium elegam is, in fact, as may be seen from Hooker's 

 figure, more closely related to PL depression and PL deplanatum 

 than to PL Borrerianum ; its diagnosis from those two species 

 I have given pretty fully above. When in fruit they are readily 

 distinguished from both PL elegans and PL Borrerianum by the 

 short pedicel ; the cernuous, asymmetrical capsule ; and the 

 rostrate lid. 



Plagiothecium Borrerianum has constantly more lustrous foliage 

 than PL elegans. The leaves have a slender point (cuspis) quite 

 wanting in the other, where they are merely acute or very slightly 

 subacuminate ; the cells, equally close and slender in both, are 

 nearly straight in PL elegam, distinctly flexuose in PL Borrerianum, 

 and in the latter there are at the base a few quadrate alar cells, 

 quite wanting in PL elegans. The female bracts, or perichaetial 

 leaves, run out to a long hair-like point. The pedicel is straw- 

 coloured, and about the same length as the red pedicel oi PL 

 elegans. The capsule is wider, thinner, and paler, merely inclined 

 at a greater or less angle, and when dry unchanged in form and 

 direction ; but the dried capsule of PL elegans is pendulous and 

 much constricted below the orifice. The lid, annulus, and peri- 

 stome differ very slightly in the two species, as is apparent from the 

 foregoing descriptions. 



Since it was first brought into notice Plagiothecium Boirerianum 

 has been found to be quite a common plant, not only in the British 

 Isles, but in almost every country in Europe, and on the eastern 

 side of North America. Like many dioicous mosses that are 

 mostly sterile, it maintains and even enlarges its area by throwing 

 out propagula, in the shape of slender deciduous rarnuli that spring 

 in fascicles of five to ten from the axils of the leaves, and are liable 

 to be washed away by heavy rains, or broken oft* and blown about 

 by parching winds, and thus transferred to other sites, where, 

 under favourable circumstances, they take root, and enter on a 

 separate existence. The same apparatus exists also in PL deprt****** 



