INTRODUCTION TO CRYPTOGAMIO BOTANY. 471 



520. All are of a dark or dingy greea The common 

 European species, as A. alpina and rv/pestris, are widely dis- 

 tributed, and not only occur in the southern hemisphere, but in 

 intermediate tropical stations. The southern hemisphere pro- 

 duces several peculiar species, and there are, besides, one or 

 two tropical representatives. Acroschisma, an antarctic genus 

 (Fig. 101), has the sporangium cleft only part of the way 

 down ; the valves vary in number, and the fruit when young is 

 involved in the oblong membranous base of the calyptra, so 

 as to have an aspect very closely resembling that of some 

 JungermaTmice. 



II. Syncladei, Berk 



Branches fasciculate. 



521. It seems so contrary, not only to distinctive characters, 

 but to natural affinity, to place the cladocarpous mosses of 

 which this division is composed, amongst the Acrocarpi, while 

 they are still farther removed from their nearest allies when 

 associated with Mielichoferei, that I feel myself constrained 

 to propose a distinct division for their reception, without, how- 

 ever, considering them, with some authors, as belonging to a 

 distinct natural order. They have, indeed, such peculiar 

 characters, that in many respects they stand apart from most 

 other mosses, and are certainly more nearly allied to An- 

 drceacei, than to any others. They are mere analogues of 

 the Leucohrya. 



1. Sphagnei, Mont. 



Sporangium globular, seated upon the top of the turbinate 

 pedunculate vaginula, within which is a very short peduncle. 

 Peristome none. Calyptra ruptured near the middle, persis- 

 tent below. Spore-sac extending over the top of the abbre- 

 viated columella. Leaves white ; cells perforated, surrounded 

 by narrow chlorophyll cells. Antheridia globose, pedun- 

 culate. 



522. The white perforated leaves, accompanied by narrower 

 cells, containing chlorophyll (Fig. 99, c), are not without 

 example in other tribes ; the sessile sporangia and calyptra, 

 bursting in the centre, have their parallel amongst Andrcmcei; 



