262 BRITISH DESMIDIACEJE. 



Closterium Navicula (Breb.) Liitkem. (vol. i, p. 75). 



Penium Navicula Breb. in W. & G. S. W. Brit. Desm. vol. i, p. 75. 

 Closterium Xai-icula (Breb.) Liitkem. Gattung Peniu/n, 1905, p. 337. 



Closterium angustatum Kiitz. (vol. i, p. 119). 

 Var. angustatum West. 



CL angustatum var. angustatum West. Clare Isl. Alg. 1912, p. 10, t. 1, f. 5. 



Variety with the striations all granular, granules 

 fairly distant, apices of the cell slightly recurved. 

 Length 457 ti ; breadth 22^. 

 IRELAND.- -Near Westport, Mayo ! 



Closterium Jenneri Kalfs (vol. i, p. 134). 

 Var. hibernicum West. 



CL Jenneri, var. hibernicum West, Clare Isl. Alg. 1912, p. 12. 



Cells longer and narrower than in the type, and less 

 strongly curved, about 120 of arc. 



o */ 



Distance between apices 116 \L ; breadth 11 [i ; breadth 

 near apices 4*5 [Ji. 



IRELAND.- -Near Westport, Mayo ! 



Closterium eboracense Turn. (vol. i. p. 140). 

 Var. achillense West. 



CL eboracense var. achillense West, Clare Isl. Ate. 1912, p. 11, t. 1, f. 13, 

 t, 2, f. 16. 



Cells always larger than in the type form, with the 

 ventral margin either slightly or distinctly tumid in 

 the median region. 



Length 255-290 ^ ; breadth 57 '5-69 p. 



IRELAND. --Near Dugort. and Slieve more, Achill Isle, 

 Co. Mayo ! 



Closterium Leibleinii Kiitz. (vol. i, p. 141). 

 Var. occidentale West. 



CL Leibleinii var. occidentale West. Clare Isl. Alg. 1912, p. 12. 



Cells not tumid in the middle, with the median part 



