NOTES ON THE BLUE-GREEN ALG&, 
WITH A KEY TO THE SPECIES OF OSCILLA- 
TORIA AND PHORMIDIUM. 
HAROLD WAGER, F.R.S. 
(Continued from page 337). 
32. In fresh water; trichomes 6-8-5 mic. broad P. tinetorium 
Stratum basifixed, elongate, waving, 
dark green, yellowish purple when dried, 
gelatinous; trichomes much constricted 
at joints; apex straight, sometimes 
tapering ; apical cell conical, no calyptra ; 
cells 5-11 mic. long, transverse walls not 
granulated. (G., 162, 4,11; T., 94, 4, 55.) 
33. Stratum incrusted with lime nde are c 
33. Stratum not incrusted with lime 
34. Trichomes 5-5-9 mic. broad, constricted at joints, Cc. okeni 
Stratum dark blue-green; trichomes 
tapering, curved or hooked ; apical cell 
obtuse, somewhat conical, not capitate ; 
no calyptra; cells 2-7-4:5 mic. long. 
Brackish water, (Gij 232; 7;.18; -L., 81, 
4, 35)- 
34. Trichomes 8-13 mic. broad, slightly constricted 
at joints 
Stratum dark green ; trichomes fragile, 
straight or twisted in loose spirals; apex 
tapering gradually, hooked or curved ; 
apical cell obtuse, not capitate, no calyptra; 
cells 3°6-8 mic. long, trans. walls with few 
orno granules. In fresh or brackish water. 
(GE 232-3: clits S236.) 
34. In salt water, epiphy tic 
Trichomes forming a delicate ‘coating 
on larger alge, long flexuous or contorted, 
constricted at joints, curved gradually, 
6-10 mic. in diameter, scarcely tapering ; 
cells 2°7-4 mic, long, transverse walls not 
granular; apical cell slightly thickened, 
somewhat capitate. On'marine alge. (G., 
218;°6, 020) 5 PEL GeyOras Ont) 
. Stratum light blue- green, floating 
Trichomes 4- 6 mic. in diameter, straight, 
fragile, not constricted at joints, tapering, 
obtuse, capitate, calyptra convex ; cells 
2°5-3°5 mic. long; transverse walls granu- 
lar. Infresh water. (G.,205; T., 62, 4, 2.) 
35. Stratum purple or purple violet 7 a3 
36. Calyptra not present; membrane may be 
slightly thickened 
36, Calyptra present . 
EWE Trichomes 5°5-8 mic. in | diameter a : 
Stratum dark blue-green; trichomes 
straight, fragile, slightly constricted at 
joints; apex curved, tapering, not capi- 
tate; apical cell obtuse, no calyptra ; 
Ww 
nn 
1913 Oct. 1. 
O. chalybea 
O. eoralline 
O. agardhii 
O. cortiana 
371 
38 
39 
40 
