122 THE JOURNAL OF BOTANY 
23. Chis. cells of br. 1. in section elliptic, median, and on both 
es completely enclosed by the slightly convex hyaline 
ell 8, which are united together for some distance; on 
the inner wall of the hyaline cells where they are united 
to the chlor. cells, almost always smooth, only in va 
rarest cases with ext remely minute aes ; stem cor 
with few fibrils xlii. S. medium Fiabe. 
24. Chlor. cells of the madils act of thie ve 1. in section wide 
epee triangular, on the outer surface completely 
sed by the 
with so-c dalled comb-fibril hich are rarely bsent ; 
transverse walls.of the seittedl cells of the branches ae 
not bent downward. St. 1. generally non-fibri 
vi. 8. ‘brie Russ. 
. Chlor. cells broadly isosceles- Sy aee with the longer 
Beds allel side on the inner surfac or a cells pit 
n-papillose ; st. 1. almos E always fibrillos 
> Chior. cells narrowly isosceles-triangular to narrow- oie 
bo 
oe 
bo 
i 
equal thickness all round, rarely somewhat thickened on 
the inner surface of the leaf ; on the outer surface enclosed 
by the strongly convex hyaline cells or free as on the 
inner surface ; hyaline cells always non-papillose ; oo 
cortex as also generally the st. 1. ler numerous fibr 
xxix. S. cymbifliun “Limpr. 
. Chlor. cells up to 15 » wide; sti cells owing to the 
great broadening of the chlor. sail remarkably narrow ; 
cells of stem cortex non-fibrillose, or only here and there 
with delicate indications of fibres; st. 1. sometimes 
non-fibrillose, sometimes with num erous fibrils. Plant 
completely submerged and in habit showing little re- 
semblance to a cymbifolium- form 
bo 
Or 
xxxvii. S. degenerans, Warnst. 
25. Chlor. cells up to 12 p wide; a broadly isosceles- 
como rasiealy trapezoid) ; hyaline cells much wider 
submerged and in habit Srerpee : " labore with 
more squarrose leaves . . . xXXviii. S turfacewm Warnst. 
Chior. cells extremely narrow ; hyaline alle non-papillose ; 
st. 1. usually without, rarely with a and their hya- 
line cells not septate xl. S. centrale 5 ensen. 
Chlor. cells wider ; valine euils on ne inner wall where 
they are united ‘to the chlor. cells always more or a 
papillose ; st. 1. oes or without fibrils and their hyalin 
cells generally se tate . . xli. S. papillosum Lindb. 
(To be cciittaned.} 
bo 
a 
) 
= 
