100 DICRANACE/E. 



areolation rectangular at base, with distinct angular cells. Seta 

 erect, capsule erect or inclined, rarely strumose, often unequal, 

 curved ; lid rostrate. Calyptra entire at the base. Peristome 

 teeth red, confluent at base, broad, cleft about half-way into 2 or 

 3 unequal divisions, minutely vertically striate below, barred 

 within. 



After a little practice the student will not have much difficulty 

 in recognising a species of this genus, but it is difficult to define 

 the characters which give it its distinctive habit ; the leaves are 

 usually falcato-secund and subulate, and the capsule has an 

 appearance rather distinctive ; the larger species could hardly be 

 taken for anything else unless for a Campylopus, and that genus 

 usually has the leaves more erect and straight. However there 

 are a few species which it would be hard to distinguish as belong- 

 ing to this genus upon first acquaintance, without microscopical 

 examination. 



The species fall somewhat naturally into the following 

 Sections : — 



A. ARCTOA. Plants autoicous, stems hardly radiculose ; 

 leaves lanceolate-subulate, entire or nearly so. Capsule very 

 small and very little exserted, or distinctly strumose when dry on 

 a longer seta. Plants usually small. 



B. EU-DICRANUM. Plants robust, the leaves usually 

 broad, mostly serrate ; lower cell-walls, and often the upper, 

 interrupted by pores. Capsule on a long seta, cernuous, more or 

 less curved, rather large. 



C. APORODICTYON. Plants dioicous ; stems radiculose ; 

 leaves subulate, entire or serrate, lower cell-walls (alone) rarely 

 porous. Capsule rather small, usually erect and symmetric, 

 longly exserted. 



/ Leaves transversely undulate 2 



\ Leaves not transversely undulate 5 



/Upper cells long and narrow, communicating by pores 3 



\Upper cells short, quadrate or irregular, not porose 4 



( Plant firm ; Is. recurved, with long spinulose teeth at margin and back of nerve 



3-^ above 6. undulatum 



|_Plant weak ; Is. with saw-like teeth, nerve almost smooth at back ...9. Bonjeani 

 J Leaves tapering, not papillose 8. Bergeri 



^ ^Leaves more suddenly acuminate, papillose above 7. spurium 



/Upper cells long and narrow, porose; plant robust 6 



5 \ Upper cells without pores 7 



,/SetK solitary ; leaves spreading or secund 10. scoparium 



\ Setae aggregate; Is. more uniformly falcato-secund 11. majus 



/Nerve J or more of base, forming a long, fine subula 20. longifolium 



'\Nerve not \ of base 8 



