106 ANNALS OF SCOTTISH NATURAL HISTORY 



OBSERVATIONS ON SOME CRITICAL SPECIES 

 OF SCOTTISH MOSSES. 



By Dr. JAMES STIRTON, F.L.S. 



THE specimen of Didymodon Jenneri (Sch.) presented to me many 

 years ago by the discoverer, the late Mr. Howie, has turned up. 

 An examination reveals the fact of its identity with Cynodontium 

 laxirete (Dixon). I have had, besides, the privilege of examining 

 the type-specimen in the Botanical Museum, Edinburgh, and it 

 agrees in every particular with mine. The long narrow leaves, from 

 4 to 7 mm. in length, are characteristic, as well as the large quadrate 

 areolation, etc. Moreover, Professor Schimper has given a detailed 

 description of the moss in the " Transactions " of the Botanical Society 

 Edinburgh, for 1868. He even mentions the shape of the cells, 

 although the dimensions are not given, as writers of his time did not 

 state such. As Howie's moss was described a quarter of a century 

 previous to Dixon's, the latter must clearly yield to the former, 

 which should now be called Cynodontium Jenneri (Sch.). This 

 moss occurs in many places in the West of Scotland. It has also 

 been found in Norway by Dr. Hagen, and described by him under 

 the name C. polycarpum, var. lavigatum (Hagen). I may mention 

 that the same moss was described by me in the " Annals of Scottish 

 Natural History " under the name C. polycarpoides. 



The following moss has puzzled me much and still puzzles me to 

 a certain extent, more especially as regards the areolation of the leaf, 

 and I am not yet quite certain of its systematic place, inasmuch as 

 I have only one capsule of the previous year, the teeth of which are 

 defective. It was first detected in 1880 on the northern slopes of 

 Craig Chailleach, and again in 1901 on Craig-na-Saoine, a mountain 

 several miles west of Killin. 



CYNODONTIUM ASPERELLUM. In lax, rather extended tufts, green 

 above, light brown below, from i to 2 inches in height ; stems strong, 

 simple or slightly bifurcate ; leaves laxly disposed round the stem, 

 about 2.5 by 0.6 mm., straight and spreading from an upright slightly 

 clasping base when moist, merely incurved when dry, lanceolate 

 from an oblong base, apex bluntish entire, margin entire, recurved 

 in the lower half but much more so on one side ; nerve strong, pale 

 yellow then red, breadth near base, 0.07 to 0.085 mm., solid, 

 thick, projecting much behind, slightly tapering for more than a 

 half upwards, vanishing below apex, papillose on both surfaces of 

 the pagina and back of nerve, strongly but sparsely in lower half, 

 much more faintly papillose on upper part; central basal cells 

 bluntly oblong, separate, pellucid or nearly so, 0.025 to 0.04 by 

 0.008 to o.oii mm., smaller outward, but only quadrate near and 



