574 
45-_ 
_Sheath absent . 
46. Apex of floraents ‘eutyed or ual 
Notes on the Blue-green Alga, etc. 
rocks in rapid water, on moist walls of 
water troughs,-etc. (G., 173, 5, 3-4; T., 
100, 4, 73-74-) 
Stratum widely expanded, dark green 
to dusky or reddish black, adhering; thin, 
sometimes floating basifixed : filaments 
straight or subflexuous, verdigris or blue- 
green ; cells 6-9 mic. in diameter, 2-6 mic. 
long, transverse walls frequently granular ; 
sheath more or less distinct or amorphous ; 
apex slightly attenuate, exceedingly capi- 
tate ; apical cell with rounded or depressed 
conical calyptra. On rocks in cataracts 
and rapid streams, sometimes on the 
ground in pools filled with rain; very 
common. (Gj 184795, 21, 22° 106; 
Onley le 
Stratum expanded, fragile, dark green 
or sometimes yellowish or reddish-brown ; 
filaments straight, rarely flexuous, en- 
tangled; sheath fragile or amorphous ; 
cells 4-7 mic. in diameter, 2-5 mic. long, 
not constricted, transverse walls frequently 
granular; apex slightly attenuate, calyp- 
tra spherical. On moist earth at bottom 
of walls, around pumps, cisterns, etc., 
rarely on banks of streams or on rocks 
sticking out of streams; very common. 
(Gs 187, 5,23; 243) ©, 807s 15) bore 2Os) 
47. Trichomes flexuous, upper part in a lax spiral, rarely 
uncinate 2 a ae ate O. 
Stratum dark coloured; trichomes 
slightly tapering at apex, not capitate, 
rounded or truncate, no calyptra; cells 
4-6-5 mic. in’ diameter, 2°5-6 mic. long, 
transverse walls granular. In sulphur 
waters, thermal; on rocks and trunks 
of trees. '(G., "2345 7,"24-3 “I, (83, 4,530.) 
47. Upper part of trichomes not in a spiral, 
(a) cells nearly or usually as long as broad 
(b) cells shorter than broad 
48. Terrestrial a 'P. 
Stratum thin, dark green trichomes 
about'1I-5 mic. in diameter, twisted, con- 
stricted at joints; cells -8-2 mic. long, 
transverse walls not granular; apex not 
tapering, calyptra none. On lmestone 
rocks and on moist earth, sometimes with 
P, autummale, (G:, 164, 4) 265. ison, 
4, 54.) 
48. In fresh water 
(To be continued). 
P. uncinatum 
47 
46. Apex of filaments straight or slightly curved, P. autumnale 
terebriformis 
61 
62 
foveqtennt 
64 
Naturalist, 
