64 HANDBOOK OF BRITISH MOSSES. 



in which the leaves are split in the direction of the keel. In 

 both, the perichsetial leaves are serrated or eroded at the apex. 

 Two other species of this genus occur in Europe. 



2. DICHELYMA, Myrin. 



Dioicous. Sporangium exserted (or immersed). Veil hood- 

 shaped, elongated. Peristome as in Fontinalis, but the inner 

 less cancellated. Branches two-ranked for irregular] ; leaves 

 narrow, nerved. 



1. D. eapillaceum, Br. et Schimp. ; branches two-ranked j 

 leaves scarcely falcate, ovato-lanceolate, extremely narrow 

 towards the apex, and serrated ; nerve excurrent ; sporangium 

 lateral; inner peristome cancellated above only. — Hook. §■ 

 Wils. tab. xxii. ; Eng. Bot. t. 2432. 



In alpine rivulets. Said to have been found by Dickson, 

 but it has not been observed since his time, and it is con- 

 jectured that foreign specimens were inadvertently substituted 

 for his plant when communicated to bryologists. Blindia 

 acuta, when growing in water, has sometimes been confounded 

 with it, and this may possibly have been what Dickson really 

 gathered. 



Three species are recorded as European, of which two only 

 have been found in fruit. They resemble in habit such Hypna 

 as H. aduncum or H. fluitans. The fruit grows laterally from 

 the perichsetial branch, the leaves of which are convolute. 

 In Dichelyma falcatum, which has never been supposed to be 

 a native of this country, the sporangium is much exserted, 

 springing terminally from the elongated perichsetial branch, 

 and the inner peristome is more like that of Fontinalis. 



