2 



Hobkirk : Tortula cernua. 



sect. Desmatodon, and next to the well-known T. mural is, with 

 which it has considerable affinity in the form and structure of its 

 leaves, but differs by its cernuous stumpy capsule with a short 

 beak and scarcely (if at all) twisted peristome, the latter being 

 quite typical of the old genus Desmatodon. There is a good 

 description of it in Schimper's 'Synopsis, 1 Ed. ii., and perhaps 

 a better still in Mueller (for references see Synonymy below), 

 but Schimper says of the leaves ' margine subplana,' which is 

 scarcely sufficiently definite according to our specimens, and 

 Mueller's 'margine interne revoluta' is much more explicit and 

 describes our plant exactly. There can be no doubt of the 

 correctness of the determination, as both Mr. M. B. Slater and 

 myself have very carefully examined it, and it is confirmed by 

 Dr. Braithwaite ; and it has also been carefully compared with 

 Dr. Schimper's specimen from the Salzburg Alps, in the late 

 Dr. Spruce's herbarium. 



From the records of its distribution it will be observed that 

 it is in the main an Arctic and Alpine species, preferring lime- 

 stone, and therefore its occurrence at so comparatively low 

 a level in Yorkshire is somewhat remarkable. Now that 

 attention has been called to it, it is very possible that next 

 season it may be detected by some of our active bryologists 

 in other districts of Great Britain, but as it ripens its fruit in 

 summer, it could hardly be recognised during the winter and 

 spring months. 



An idea of the very wide distribution of this species will be 

 gathered from the following published records : — Starting in the 

 far East, Mitten records it from the Alpine regions of Eastern 

 Thibet, gathered by T. Thompson ; in Europe we have it from 

 the Alps of Germany, Austria, Switzerland, and Italy, e.g., 

 Schleherngebirge (Treviranus) : prope Juvaviam (Sauter) ; in 

 monte Kramer prope Partenkirchen, 5,000 feet (Arnold); near 

 Meran (Bamberger) and near Trafoi (Schimper), both in the 

 Tyrol; in the Valley of Aosta, St. Bernard; and in the Salz- 

 burg Alps (Schimper), in herb. Spruce ; also on the Island of 

 Langden, Finmark, on the sandy marge of the glacial sea 

 (Wahlenberg), and numerous other places in Sweden and 

 Norway ; in North America, from the Rocky Mountains 

 (Drummond) ; in Canada, at South-West Point, Island of 

 Anticosti ; Campbelton, New Brunswick ; along the Pembina 

 River, N.W. of Edmonton, N.W. Territory ; Cache Creek 

 Mountain ; in a ravine at Kamloops in British Columbia 

 (Macoun) ; and in Greenland .(Flora Grcenl.). 



Naturalist, 



