NEW AND RARE SCOTTISH MOSSES 105 



which has, besides, minute structural differences as revealed 

 by the microscope, that I cannot reconcile myself to its 

 identification with any of the other forms. This condition 

 is also so constant that the moss may be discriminated by 

 the naked eye. In all these multifarious forms there is only 

 one constant character, viz. the presence of groups of 

 sterei'd cells on botJi sides of the middle row of cells, which a 

 thin section of the nerve reveals. This structure of the 

 nerve, as is well known, is almost unique amongst the 

 European Campylopi, and is reckoned of such importance by 

 one or two bryologists as to warrant a separation of the 

 moss into a new subgenus under name Palinocraspis (Lindb.). 

 I may mention that in Lewis the vast majority of the forms 

 of C. brevipilus are without hyaline hair-points. 



Campylopus fulvoviridis forms often widely extended, 

 very compact tufts, generally plane above, not convex, and, 

 in a wettish state, nearly continuous in such a humid 

 atmosphere, these tufts have a peculiar glistening appearance 

 which attracts the eye at once, dark-green above, brownish, 

 brownish-black, or even black below, with a few pale radicles, 

 or at times with scarcely any ; stems slender, simple or 

 sparingly dichotomously branched ; leaves rather crowded, 

 erect or somewhat erecto-patent, not differing much in 

 direction in a dry state, slender and flexile, narrowly 

 lanceolate, nearly tubular above, shortish and but slightly 

 acuminate, bluntish at the apex and toothed there and 

 often down the margin, as well as presenting, very often, 

 blunt hyaline teeth on the back of the nerve, muticous and 

 without auricles ; central basal cells hyaline, oblong or 

 rhomboid or, at times, oblongo - hexagonal, 25 to 45 

 by 9 to 14 yit, narrower outwards, and near the margin from 

 5 to 10 rows of very narrow elongated cells all this 

 space hyaline, and sloping upwards at an acute angle to the 

 margin, up from this all cells fully chlorophyllose, rhomboid 

 or narrowly rhomboid, towards the apex cells smaller, 

 rhomboid, oval, or frequently bluntly triangular, 10 to 17 

 by 5 to 7 /JL ; nerve thin, 27 to 36 ^ thick, from one-third to 

 a half the breadth of the leaf near the base, not bulging in 

 the middle, tapering upwards, and slightly excurrent or, at 

 times, scarcely so, section of the nerve shows three rows of 



