go DICRANACE^E. 



growths in the form of protonemoid filaments, afford a means of 

 propagating the species. The measurements of the width of the 

 nerve are taken just above the auricles when these are present. 



The number of layers of cells in the nerve as shown in 

 section is a character of slight value, as is also the presence or 

 absence of furrows on the dorsal surface, except in the case of 

 C. introflexus ; Limpricht has however pointed out two distinct 

 types of structure in these cells which are quite constant, and by 

 which the species may be divided into three groups; (i) C. 

 brevipilus ; unique in having the single layer of wide thin- 

 walled empty cells median (Tab. XVI. I. lx). (2) C. subulatus, 

 C. Schimperi, C. Schwarzii, C. Shawii ; in all these the layers 

 (usually about two) of thin-walled larger empty cells are anterior, 

 and the posterior layers while variable in size, etc., are uniform, 

 moderately incrassate (Tab. XVI. A. lx). (3) All the remaining 

 species have the same anterior series of thin-walled cells, but the 

 dorsal layers are composed of two forms of cells, small groups of 

 minute, very incrassate cells, almost without lumen, being inter- 

 spersed between the larger ones (Tab. XVI. E. lx). 



{Leaves with hyaline points 2 

 Leaves without hyaline points 4 



{Hyaline points short ; nerve with central large cells g. brevipilus 

 Hyaline points usually long ; nerve with anterior layer of thin cells 3 



,/Ls. auricled, dark-green ; upper cells long and narrow 7. atrovirens 



3\Ls. not auricled, olive-green; upper cells short 8. introflexus 



Ls. not (or scarcely) auricled at base 5 



{Ls. not (or scarcely) auricled at base . . . 

 Ls. auricled at base with swollen cells 



/Ls. straight, entire; cells near base very narrow 6 



■" \ Ls. almost setaceous, serrulate towards apex ; basal cells lax 7 



,/Stem £ inch, not radiculose 1. subulatus 



\ Stem taller, densely tomentose /*. Schimperi 



I Nerve about J/$ of base of leaf; lamina usually widest at base 4. pyriformis 



7-j Nerve about )/% base ; ls. from longer base, lamina narrowed at insertion 



[ s- fragilis 



o/Ls. strongly serrate above ; stem tall, not radiculose 6. setifolius 



\Ls. entire, or serrulate near apex only 9 



fNerve y 3 -y 2 of base of leaf 4. flexuosus 



y \Nerve % or more of base 10 



f Ls. gradually tapering almost from base, entire 2. Schwarzti 



10-j Ls. with longer and wider base, more suddenly narrowed to the long 



y subula, denticulate at apex j. Shawii 



1. Oampylopus subulatus Schp. (C. brevifolius Schp., Syn.) 

 (Tab. XVI. A.). 



Very short, yellowish, resembling the small forms of C. 

 fragilis, but with shorter, more rigid leaves ; stems slender, 

 fragile, \-\ inch in height, densely gregarious or loosely tufted, 

 not radiculose above. Leaves short, erect, rigid, from an oblong 



