Moore— 0/i the 3Iosscs of Ireland. 
461 
Tor full descriptions of the histology of this singular tribe, see Dr* 
Schimper's Monograph, " Entwicklungs-Geschichte d.Torfmoose" 
(1858). Also, papers On bog mosses," published by Dr. Eraith- 
waitCj in the ''Monthly Microscopical Journal," vol, yi. (1871). 
Louis Pire '' Les Sphaignes de la Flore de Eelgique," in Soc. 
Eoy. Bot. Eelg. Bulletins, torn, yi., '^o. 3 (1867). The genus 
Sphagnum is now kept apart from other mosses by most 
authors, and placed as an intermediate group between Mosses 
and Hepaticse The Sphagna differ from other mosses chiefly in 
the following points: — Yfhen vegetating, they do not produce 
the usual confervoid prothallium of typical mosses, but a lobed 
foliaceous prothallus, resembling that of frondose Hepaticse. 
The main stems also are unlike those of mosses in having three 
distinct layers, viz. — first, a kind of medulla of long cylin- 
drical cells, next, a kind of mesophleum of prosenchymatous 
cells, and outside a sort of bark-layer or stratum of thin-walled 
cells, larger than the others. The male flowers also differ in 
their arrangement, and in form ; the pedicellate antheridia are 
like those of Hepaticse. The female flowers present other dis- 
tinctions, which have already been noticed in the general charac- 
ters of the tribe. 
Diagnosis of Species. 
a. Cortical cells of branches lined with spiral fibres. 
Stem-leaves Ungulate- spathulate, blunt at 
apex; branch-leaves broadly ovate, cu- 
cuUate at apex. Dioicous, . . , 1. S. cymbifolium. 
aa. Cortical cells of branches without spiral fibres. 
Hyaline cells of stems not fibrillose. 
Stem-leaves obovate, obtuse, much fringed 
at the apex, hyaline cells large ; branch- 
leaves ovate-lanceolate, acuminate. Mo- 
noicous, . . . . , . 2. S. fimbriatuMo- 
Stem-leaves very obtuse at the apex ; branch- 
leaves ovate- lanceolate, acuminate. Dioi- 
cous, 3. S. GIRGENSOHIfll^ 
Stem-leaves ovate, obtuse, with irregularly 
shaped hyaline cells; branch-leaves 
elliptic, obtuse, of a purplish-red colour. 
Dioicous, , . . . . . 4. S. eubelluMo- 
