Hypnace^.] 42 [Amhlystegium. 



Var. y. hamatum {Schimp.) Lindh. 



Plants robust, more rigid, regularly pinnate, the branches patulous. 

 Leaves denser, fuscous, elongated, circinate, cuspidato-acuminate, strongly 

 nerved to apex. 



Syn. — Hypntim aduncum Var. € hamatum et t, giganteum Schimp. Bry. eur. fasc. 55 — 56, t. 25. 

 Synops. 607. 



Hypniim hamifolium Schimp. Synops. 2 ed. 732. 



Amhlystegium Wilsoni Var. hamatum Lindb. Muse, scand. 33. 



Hab. — Deep bogs, very rare. 



Lough Neagh, Ireland {Rev. C. H. Waddell 1886) ! ! Pools at Castlethorpe, Northants 

 (Dixon 1889) ! ! 



This and the following 8 species constitute a most difi&cult group, as like 

 most aquatics they are extremely variable. Two recent writers have made a 

 special study of them, i, Sanio in Bot. Centralblatt xiii, and Svenska vet. 

 akad. Handl. x, in which the nine species are reduced to six, under which are 

 placed a great number of varieties, subvarieties and forms and hybrids are 

 also established. 2, Renauld in Husnot's Muscologia gallica, where nine 

 species are maintained and a great many varieties, the whole described with 

 great care and acumen. For the purposes of this work I have preferred the 

 simpler arrangement of Schimper, and would merely point out that the 

 leaf-cells and structure of the leaf-base are the parts most deserving 

 attention. 



23. AMBLYSTEGIUM INTERMEDIUM Lindb. 



Dioicous ; resembling A . Sendtneri, but more slender, pale green, 

 vaguely pinnate. Leaves from ovate-oblong, lanceolate, not sulcate, 

 the acumen flexuose and twisted, the cells very narrow and vermicular ; 

 lower perichaetial bracts numerous, squarrose. (T. XCIII, A.) 



Syn. — Hypnmn intermedium Linde. in Hartm. Skand. fl. 9 ed. 17 (1864). Milde Bry. siles. 

 352 (1869). BouLAY Muse. Fr. 56 (1884). Sanio Besehr. der Harpid. 57 (1885). 



Hypnum Cossoni Schimp. Bry. eur. Suppl. fasc. 3 — 4, t. 5 {1866), Synops. 2 ed. 730 

 (1876). HoBK. Synops. 2 ed. 217 {1884). 



Hypnum revolvens * Cossoni et intermedium Renauld in Rev. bryol. 1881, p. 79, et in 

 HusN. Muse. gall. 391 ut Var. (1894). Dix. James. Stud. Handb. 465 (1896). 



Amhlystegium intermedium Lindb. Muse. Scand. 33 (1879). 



Dioicous ; pale yellowish green above, fuscescent at base. Stems 

 3 — 10 in. high, flexuoso-erect, interruptedly pinnate, the branches very 

 unequal. Leaves densely crowded toward apices, falcato-secund, from 

 an ovate-oblong base slightly decurrent at angles, lanceolate, concave, 

 not sulcate, with a short or long fine acumen, often flexuose or spirally 



