SOME SCOTTISH MOSSES 113 



stems of Bryum barbatum were detected amongst those of the 

 other moss, showing distinctly even to the naked eye. 



BRYUM LEPTALEUM, ;/. sp. Tufts compact, one inch 

 in height or a little more, bright green above, rich red or 

 rather a wine-red colour below, densely matted with strong, 

 papillose, red radicles ; stems very slender and fragile, 

 simple or dichotomously branched, leaves rather laxly dis- 

 posed, spreading a little when wet, laxly accumbent when 

 dry but not twisted, broadly or rather roundly and shortly 

 ovate, a little decurrent, very concave, abruptly extended 

 into a fine, tapering, greenish, slightly reflexed acumen 

 (length 14 to 20 //,), length of leaf 75 yu,, or including the 

 acumen 90 /A, breadth 60 JJL, rarely of greater dimensions ; 

 margin plane or slightly platter-shaped below, entire ; nerve 

 tapering upwards, breadth near base about 35 /A, reaching 

 only rather more than half the length of leaf; areolation 

 near base oblong or oblongo-hexagonal, 40 to 50 by 16 to 

 20 yu-, near apex smaller, more distinctly hexagonal, 32 to 40 

 by 1 6 fj,, marginal, in one, at times two rows, longer but 

 scarcely narrower except near the apex where they are 

 about 1 2 ^ broad ; all cells chorophyllose. Structure of 

 leaf very thin and delicate. 



This moss, I need scarcely say, differs from B, barbatum 

 in the shape of the leaf, size, etc. (that of the latter is twice 

 the length of the other, its areolation larger), in the nerve, 

 which is excurrent, and in the disposition of the leaves 

 round the stem. 



The leaf of Plagiobryum Zierii bears a resemblance to 

 that of the present moss, but in the former the nerve 

 vanishes just at base of apex which is short, and it has 

 larger nearly colourless areolation. The whole habit of P. 

 Zierii is besides quite different. 



The next moss is also due to Mr. D. Haggart who 

 discovered it on Ben Lawers in July 1902. It may be 

 said to be almost a hybrid between Dicranum fuscescens and 

 D. Starkii or D. Blyttii. 



DICRANUM MEDIELLUM, n. sp. The perigonium is 

 always close to the perichaetium, except in one instance, 

 where it was found in the axil of the fourth or fifth leaf 

 46 E 



