36 F. E. FEITSCH. 



RIVULARIACE^. 



Genus Calothrix Agardh. 



54. Calothrix Antarctica sp. n. 



(PI. III., figs. 161-163.) 



Fills solitariis vel sparse congregatis, flexuosis, usque ad 300 ju, longis, in stratu 

 Phormidii fragilis nidulantibus ; vaginis crassis, flavescentibus, indistincte lamellatis, 

 non ocreatis, spatio parvo a trichomatibus sejunctis, ssepe apice diffluentibus ; betero- 

 cystis basilaribus, solitariis vel rare duabus, plerumque non in vaginis inelusis, ellipticis. 

 vel plerumque deplanatis membrana crassa et contentu homogeneo, ssepe effetis ; 

 trichomatibus paulatim apicem versus attenuatis, ut videtur non in pilum productis, 

 interdum pseudo-ramosis, inter cellulas plus minusve constrictis, dissepimentis indis- 

 tinctis, ssepe granulatis ; cellulis ad basim trichomatis modice deplanatis, sursum 

 paulo longioribus quam latis, cytoplasmate cum paucis granulis magnis. 



Diam. fil. ad bas. = 10-15 ju,; diam. trich. ad bas. = 6-8 /x ; diam. fil. in media 

 parte = 8-13 /a ; diam. trich. in media parte = 5-6 /a; diam. heterocyst. = lO/x,; crass. 

 parietis vaginae = 2 ju,. 



Hob. — Freshwater 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. fusca (Kiitz.) Bornet et 

 Flahault, but the latter difi"ers 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. 



(PI. Ill, figs. 158-160.) 



Fills in stratu parvo membranaceo dlsposltis dense flexuoso-contortis et Intrlcatis 

 vel subsolitarils, subbrevibus, ut videtur usque ad 300 yu, longis, ad superficlem 

 Phormidii affixls ; vaginis tenuibus, distinctis, achrols, non ocreatis, plerumque arctls, in 

 basi Interdum paulo inflatls ; heterocystls basilaribus, singulis vel pluribus, plerumque 

 in vaginis inelusis, plus minusve hemisphsericis vel deplanatis, contentu interdum 



