350 FRESHWATER AL^ OF LISMORE DISTRICT, 



and of the gonidia. The trichomes and gonidia were very pale 

 blue, almost hyaline. A delicate sheath was distinctly observed. 



Genus Plectonema Thuret. 

 Plectonema nostocorum Bornet. 



Plentiful, much branched, almost hyaline, in a mucilaginous 

 stratum with other Lynghyece. I have never found this species 

 pale yellow-green, as noted by Gomont, Monog. d. Oscill., p. 103; 

 but almost all the blue-green Lynghyece have a yellow-green 

 form. 



Lismore(213). 



Plectonema crispatum, n.sp. (PL xlvi., f.2.) 



Stratum sordide olivaceum. Fila primum sessilia csespitosa, 

 deinde arete intricata, abundanter pseudo-ramosa, pseudo-ramis 

 solitariis, curvatis. Vaginae distinctse hyalinse. Trichomata 

 pallide aeruginosa paene hyalina, apicibus conicis, ad genicula 

 baud constricta, protoplasmate homogeneo. Dissepimenta dis- 

 tincta baud granulata. 



Trich. diam. 2-3, cell. alt. 1-2 /x. 



Lismore(210). 



Found as a pinky-brown stratum on a zinc-footwasher at the 

 Presbyterian Church. Other parts of the stratum, however, 

 were dull green, and the purple colouration was found to be 

 entirely due to inert vegetable debris. The trichomes themselves 

 were very pale blue, almost hyaline. 



Genus Lyngbya C. Ag. 

 Lyng. iERUGiNEO-c^RULEA (Kiitz.) Gomont. 

 Trich. diam. 6-8, cell. alt. 2-4, plerumque 2 J /x. 

 Lismore(199). 



Trichomes strongly blue-green; dissepiments very distinct, in 

 the larger trichomes apparently minutely granulate: ends conical 

 or rounded. Sheath noted. 



Lyng. Kutzingii var. DiSTiNCTA(Nord.)Lemm. (PI. xlvi., f.3) 

 Trich. diam. 1 J-2, cell. alt. circa 1 J /x. 

 Lismore(201, 206,211). 



