BRYUM. 321 



shortly excurrent, or vanishing at or below apex ; not red at 

 base. Capsule on a rather short seta, (5-7 lines long), pendulous, 

 oblong-pyriform, with the neck about equal in length to the cap- 

 sule ; lid convex or slightly mamillate ; peristome teeth deep 

 yellow, darker at base, resembling those of B. inclinatum. 

 Synoicous. 



Hab. Crevices of limestone rocks, nr. Litton, Yorkshire (Whitehead, i8yg). 



This species, which has only been found in Britain in the single locality named, 

 is a Scandinavian plant, rare on the continent. It appears to be somewhat inter- 

 mediate between B. inclinatum and B. Icuustre, differing from the former in the 

 leaves with the margins little recurved, and the nerve much less longly excurrent, 

 with the cells — so far as I have been able to observe them, very little narrowed at the 

 apex, while in B. inclinatuvi they become very narrow there ; B. lacustre has more 

 concave leaves with the margins widely recurved. The brownish purple colour is 

 also said to be constant. 



7. Bryum lacustre Brid. (Mnium lacustre Bland.) 

 (Tab. XLIII. F,). 



Loosely tufted, more or less reddish, short. Lower leaves 

 widely ovate, upper ovate, shortly acuminate , concave, margin 

 entire or nearly so, revolute usually almost to summit, not 

 bordered or with a faint border of narrow cells, nerve reddish, 

 ceasing below apex or percurrent, rarely a little excurrent ; cells 

 short, wide, not much narrowed at apex. Seta slender, capsule 

 small, shortly pyriform, with a neck shorter than the capsule, 

 small-mouthed, inclined, more rarely pendulous, when dry and 

 empty wide-mouthed ; lid apiculate, peristome small, pale ; teeth 

 yellow, orange at base. Cilia rudimentary. Synoicous. 



Hab. Sandy places, rare. Fr. summer. 



In habit and leaf this comes, perhaps, nearer B. Warneum than any other 

 species, but the peristome is that of the Section Cladodium, and by this it may be known 

 at once. In this respect it more resembles B. calophyllum, but that has more obtuse 

 leaves, with the margin hardly recurved and with scarcely any border, and the 

 inflorescence is autoicous ; in the present species there are usually some rows at least 

 of somewhat narrowed cells at the margins of the leaves. B. Marratii differs in the 

 differently-shaped capsule, the deep orange teeth and obtuse leaves ; B. inclinatum in 

 the narrower leaves with more acuminate points and more excurrent nerve, and the 

 cells at apex narrow. 



B. origanum Bosw. may possibly belong here. Braithwaite makes it a synonym 

 of B. fallens, but the leaves, in the only original specimens I have seen, from 

 Boswell's herbarium, gathered by Wesley in 1879, are not or scarcely decurrent, with 

 the margin plane or very lightly recurved, and entirely without a border in most 

 cases, or with a single row of hardly narrowed cells in some leaves ; the nerve is 

 markedly thick throughout the greater part of its length, and prominent at the back. 

 On the whole it appears to me much more similar to B. lacustre than to B. fallens, 

 but it is one of those barren plants which frequently occur in this genus, and which it 



