FRESHWATER ALGÆ FROM TUDDAL IN TELEMARK. 163 



63. ? Penium subtile. W. & G. S. West. 



I have observed a single specimen of a desmid, which bare 

 a striking resemblance to P. subtile. I do not, however, venture 

 to identify it as P. subtile. 



64. Penium Gucurhitinum. Bissett. 



Generally distributed in the bogs. Up to 4100 feet. Size: 

 long, 67 «, lat. 25 ,«. 



64 a. forma minor. W. & G. S. West. 



This form may also be quite general, but I have not always 

 seperated it from the type. Size: long. 56,5,«, lat. 25«. Long 40 ^<, 

 lat. 20 1^1. Small form, but quite typical. PI. IV, Fig. 4. 



65. Penium cruciferum. (De Bary) Wittr. 

 var. pluriradians. Wittr. 



Very rare. 



66. Penium inconspicuum. W. West. 



Very rare, but it is possible that I have overlooked it, owing 

 to its minute size. Size : long. 14 /li, lat. 5 ^u. 



67. Penium minutum. (Ralfs) Cleve. 



General, and often in abundance. I have not distinguished 

 between its various forms. A measurement: long 98 ^^, lat. 11 (.i. 



Genus Closterium. Nitzsch. 1817. 



68. Closterium, Archerianum. Cleve. 



Specimens of this desmid were by no means uncommon. 

 The most forms were intermediate between the type and CI. 

 porrectum var. angustatum. It is very probable (hat CI. Archeria- 

 num should not be separated from CI. porrectum, but he placed 

 as Closterium porrectum var. Archerianum (Cleve) nob. (CI. porrec- 

 tum was described 1870, CI. Archerianum 1871). 



69. Closterium reguläre. Breb. 



This rare species was uncommon, and I have only 

 noticed it from a single sample. Size: long. 280 //, lat. 28 ^, 

 12 costæ. 



