196 MR. W. WEST OS TIIE FRESnWATER 



1. ElYTJLARTA CALCAREA, Sm. Fvg. Bot. (tab. 1799). 



1. Near Westport. 



2. E. granulieera, Carm. (Cooke, Br. Fresh iv. Alg. pi. 115 



% i.) 



Diam. trich. 4-12 /z. 

 > II. Tore Mt. 



3. E. echinata, Cooke. (Cooke, I. c. tab. 114. i 

 I. Lakes Dear Eecess. 



V * 



Ord. ScYTONEMACEiE. 



1. Tolypothrix Aegagropila, Kuetz. (Babh. Fl. Europ 

 Alg. ii. p. 274.) 



Articulis diametro paulo longioribus. 



Diam. trich. cum vag. 15 /z. 



I. Lakes, Clifden to Eoundstone. 



2. T. pygmea, Kuetz. (Rabh. I.e. p. 275.) 

 Diam. trich. 8-10 /z; long, heterocyst. 8-5-10 /z; crass, hete- 

 rocyst. 6-5-8-5 /i. 



I. Lakes, Clifden to Eoundstone. 



A small form (diam. trich. 6*5-7^) with single heterocysts was 

 noticed which may belong to T. tenuis, Kuetz. 

 I. Athry Lake. 



1. Petalosema alatum, Berk. [Arthrosiphon alatus ( Grev.), 

 Babh. I. c. p. 265.] 



1. Ballynahinch. 



tl. Scitokema calotrichoides, Kuetz. (Babh. Fl. Europ. 

 Alg. ii. p. 253.) 



Lat. sine vag. 12*5-13 /i; lat. cum Yag. 17-20 /z. 



II. 8 m. S. of Kenmare. 



A form with the branchlets both geminate and single, they 

 were also frequent ; the heterocysts differed frtm those of the 

 type in being rotund-elliptic. 



Lat. trich. sine vag. 7-8 /i ; cum vag. 9-11 /i. 



II. Cromagloun. 



2. S., sp. 



Diam. trich. 12-15 fj ; cum vag. 23-25 p. 



