FRESHWATER ALG.E. 29 







35. LYNGBYA SCOTTI * sp. n. 

 (PI. II., figs. 91-93.) 



Fills august is, plerumquc valde tortuosis, interdum subrectis, stratum in superficie 

 Phormidii formantibus ; vaginis prirao tenuibus hyalinis, demum modice incrassatis 

 extus rugosis cum particulis numcrosis adhserentibus, non lamellatis ; trichomatibus 

 cum cellula apical! acuta coiiica, uon capitatis aut attenuatis, plerumque modice inter 

 cellulas constrictis ; cellulis tarn longis quam latis vel paulo longioribus, plerumque 

 cytoplasmate homogeneo, dissepimentis indistinctis, sed interdum cum granulis dense 

 aggregates in utraque parte dissepimentarum ; calyptra uulla. 



Diam. fil. = 3 '4-5 p. ; diam. trich. = 2 '6-3 //,. 



lid). Granite Harbour, January 20th, 1902. 



This species should be compared with Lymjbya kutzingi Schmidle, and its 

 variety distincta (Nordst.) Lemm. (= L. suit Hi* West). It differs from these forms in 

 the thickened rugose sheath of older filaments, in the acutely conical apical cell, the 

 slight constriction between the cells and the occasional granulation of the dissepiments. 

 The adhesion of small particles to the rough surface of older sheaths is a marked 

 characteristic, as the bulk of the filaments showed it. 



Var. MINOR var. nov. (PI. II., figs. 94-96). 



Filis augustioribus, plerumque valde tortuosis ; vagiuis tenuibus hyalinis ; 

 trichomatibus cum cellula apicali acuta conica, interdum paulo attenuatis, modice inter 

 cellulas constrictis ; cellulis tarn longis quam latis vel paulo longioribus, contentu 

 homogeneo. 



Diam. fil. = 2 5-2 7 ^ ; diam. trich. = 1 5-1 8 ju,. 



Ilab. Gap pond, Winter Harbour, February 20th, 1904 (forming a stratum on 

 Phormidium). 



This variety differs chiefly from the type in its smaller dimensions and in the 

 apparent absence of thickening of the sheath in older filaments. The cell-contents 

 were in all cases homogeneous. 



36. LYNGBYA LAGERHEIMI. 

 (PI. II., figs. 74-78.) 



Lyngbya lagerJieimii (Mob.) Gomont, torn, cit., pp. 147-148, PI. IV., figs. G, 7 (Spirocoleus laffer/ieimii 

 Mobius, Hedwigia, 1889, p. 312, Tab. 10, figs. 1, 2). 



Diam. fil. = 3-3 '5 p ; diam. trich. = 2-3 /*. 



Ilab. Freshwater pond in eskers upon ice, halfway between Black Island and 

 Brown Island, January 3rd, 1903. 



* This species is named after Captain Scott, C.V.O., the leader of the British National Antarctic Expedition 

 [and of the British Antarctic Expedition, 1910] . 



