NEW AND RARE MOSSES 173 



what irregular in outline, about .035 mm., diam., at first dark green ^ 

 then brown. 



In July of 1863, on almost the first occasion of a visit to the 

 summit of Ben Lawers, I picked up a small Mnium whose leaves 

 are almost an exact counterpart in size and shape, as well as in the 

 abbreviated nerve, of those of the pretty little M. hy77ienophylloides 

 from Norway ; but as the upper margin of the leaf has double 

 spinulosities this moss must be classified under a different section, 

 and near M. orthorrhynchum. 



Mnium gracilentum {n. sp.) — In laxly aggregated tufts or 

 scattered, stems about half an inch long, mostly simple, of a deep 

 red colour, slender, bare below, or with a few minute scale -like 

 leaves, while above, the leaves are rather closely aggregated and 

 somewhat crisped when dry, spreading a little when moist, broadly 

 rotundato-ovate, much narrowed at the base, bluntish at the apex 

 with a short acute mucro, length, .02 mm. ; margin in the lower half 

 or thereby plane, entire, composed throughout its length of two, 

 rarely three longitudinal rows of long narrow cells with thin walls, 

 .08-. I by .006-. 008 mm., while the upper margin has a double row 

 of short, bluntish, one-celled spines ; the rest of the cells of the 

 pagina are nearly uniform throughout, viz., bluntly or roundly 

 quadrate with thickish walls, .016-.022 mm. across, a very little 

 larger near the base; nerve slender, latit. near the base .05-.06 

 mm., tapering upwards, and ceasing below apex by about .08 mm.; 

 margin, spine, and nerves become ultimately a deep red colour. 

 Average dimensions of leaf, 1.6 by i.i mm. On the ground near 

 the summit of the mountain. 



The species of the genus Philonotis have throughout a series of 

 years exercised ray ingenuity to discriminate them. Amongst those 

 of later years that have attracted my attention is the following. It 

 was found in 1867 near the summit of Ben Lawers, and although 

 its peculiarities were noted at the time it was laid aside and only 

 rediscovered the other day. It is evidently allied to Ph. adpressa 

 (Ferg.), but the differences between the two are manifest and very 

 peculiar. 



Philonotis heterophylla, 7i.sp. — Tufts lax and often ex- 

 truding its stems through other mosses. Not unfrequently the 

 upright stems were seen to arise from a horizontal stock thickly 

 covered with red radicles. These upright secondary stems are 

 from one to two inches long, either simple, or sparingly and 

 shortly branched, or occasionally dichotomously divided. In the 

 lower half of the stem the leaves are laxly disposed around it, but 

 closely appressed both in a wet and dry state, broadly ovate, concave 

 with either sharp or bluntish apices, rounded at base as well as 

 narrowed at point of insertion, margins only narrowly reflexed near 



