36 Y. E, FRITSCH. 
RIVULARIACEA. 
Genus CaLoTHRix Agardh. 
54, CALOTHRIX ANTARCTICA sp. 0. 
(PL IIL, figs. 161-163.) 
Filis solitariis vel sparse congregatis, flexuosis, usque ad 300 longis, in stratu 
Phormidii fragilis nidulantibus ; vaginis crassis, flavescentibus, indistincte lamellatis, 
non ocreatis, spatio parvo a trichomatibus sejunctis, seepe apice diffluentibus ; hetero- 
cystis basilaribus, solitariis vel rare duabus, plerumque non in vaginis inclusis, ellipticis 
vel plerumque deplanatis membrana crassa et contentu homogeneo, sepe eftetis ; 
trichomatibus paulatim apicem versus attenuatis, ut videtur non in pilum productis, 
interdum pseudo-ramosis, inter cellulas plus minusve constrictis, dissepimentis indis- 
tinctis, seepe granulatis; cellulis ad basim trichomatis modice deplanatis, sursum 
paulo longioribus quam latis, cytoplasmate cum paucis granulis magnis. 
Diam. fil. ad bas. = 10-15; diam. trich. ad bas. = 6-8; diam. fil. in media 
parte = 8-13; diam. trich. in media parte = 5-6; diam. heterocyst. = 10; crass. 
parietis vaginae = 2 p. 
Hab.—¥reshwater pond in eskers upon ice, half-way between Black and 
Brown Islands, January 3rd, 1903. 
This species was relatively rare, but very distinct owing to the yellow colouration 
of the sheath; this is thick, faintly stratified and diffluent at the apex. It does not 
appear that the trichomes terminate in a hair, although I do not feel sure on this 
point. The trichomes showed no constriction at the base, but in the upper portions 
frequently appeared almost moniliform (fig, 162). The granulation of the dissepiments 
(figs. 161, 163) is not a common feature in the genus. 
C. antarctica appears to be rather closely allied to C. fusea (Kiitz.) Bornet et 
Flahault, but the latter differs in the bulbous inflation of the base of the filaments, 
the colourless gelatinous sheaths, the short cells and probably in the production of 
the trichomes into a long hair. The characters of the sheath also serve to distinguish 
this species from C, sandvicensis (Nordst.) Schmidle. 
55. CALOTHRIX INTRICATA sp. n. 
(Pl. III., figs. 158-160.) 
Filis in stratu parvo membranaceo dispositis dense flexuoso-contortis et intricatis 
vel subsolitariis, subbrevibus, ut videtur usque ad 300, longis, ad superficiem 
Phormidii affixis ; vaginis tenuibus, distinctis, achrois, non ocreatis, plerumque arctis, in 
basi interdum paulo inflatis ; heterocystis basilaribus, singulis vel pluribus, plerumque 
in vaginis inclusis, plus minusve hemisphzericis vel deplanatis, contentu interdum 
