Wilson's notes on British muscology. 370 



mouth a little contracted. Operculum subulate. Calyptra 

 dimidiate, twisted. Setae frequently two or three together. 

 Vaginula cylindrical. Perichaetial leaves very small. Leaves 

 composed of a somewhat granular substance, fragile, minutely 

 scabrous in the margin, which is nearly plane. 



This species was observed in several stations in North 

 Wales, viz., in the rocky dell above Dolgelley, and by the 

 roadside leading westward under Cader Idris ; also near Pont 

 Aberglaslyn, one mile from Beddgelert. It has likewise been 

 found in Ireland near Killarney, by Dr Taylor, but in a per- 

 fect state it appears to be one of the very rarest of our Bri- 

 tish Mosses. 



15. IVeissia affinis — Before this Moss can be established 

 as a good species, further investigation seems to be requisite. 

 If any permanent mark of difference exist between it and 

 Gymnostomum conicum^ it will be found not in the peristome, 

 which is extremely variable, but in the form of the capsule, 

 which in Weissia affinis is elliptical, and somewhat contracted 

 at the mouth. After having bestowed much pains in the ex- 

 amination of numerous specimens, I am compelled to leave 

 the question undetermined. 



16. Fissidens osmundioides. — An essential difference be- 

 tween this Moss and Dicramim bryoides of Muse. Brit., has 

 long ago been pointed out by Wahlenberg, and since verified 

 by Meyrin and the writer of this note. The calyptra is mitri- 

 form, with the margin strongly turned inward, and the 

 leaves are destitute of the cartilaginous margin observable in 

 Z). bryoides, which has the calyptra truly dimidiate, and a 

 shorter operculum. 



17. Dicranum Schreherianum. — The genuine Moss figured 

 in Hedw. Sp. m. /. 33, has been found in Lancashire, and 

 more recently near Glasgow. The lid is shorter than in the 

 Moss found in Glen Tilt, which is either a well marked varie- 

 ty, or more probably a distinct species, for which Bridel pro- 

 poses the name D. GreviUeanum* 



18. D. polycarpum has been recently found on Cader Idris 

 by Mr Half. 



