164 KAARE MÜNSTER STRØM. 



70. Closterium striolatum. Ehrbg. 



General, and often in abundance. The most of the speci- 

 mens were colour-less. A form was observed with distinct granules 

 between the striae, an other form with granules on the dorsal 

 half. Size : long. 240 in, lat. 42 ,«. 



71. Closterium Ulna. Focke. 

 var. constridum. var. nov. 



Differs from the type in having : slight but distinct constric- 

 tion, broader apex, strong yeltow-brown colour, and very thick 

 cell-wall. About 13 striæ visible. Size : long. 294 /.i, lat. max. IS ft, 

 lat. med. 16 /li, lat. apic. 13,5 /n, crass, mem br. 2,5 /n. 



72. Closterium juncidum. Ralfs. 

 Fairly general. 



73. Closterium Dianæ. Ehrbg. 

 General. Most specimens colour-less. 



74. Closterium parvulum. Näg. 

 Not uncommon. 



75. Closterium Jenneri. Ralfs. 

 Somewhat rare. 



76. Closterium Venus. Kütz. 



Fairly general, but never in great abundance. 



77. Closterium Leibleinii. Kütz. 



Fairly general. Size: long. (= dist. apic.) 120 f,i, lat. 16,5 /n. 

 Slender form. 



78. Closterium tumidum. Johnson. 



Frequent, and sometimes in quantity. Size: long 95 ji/, lat. 12^i. 



79. Closterium, Cornu. Ehrbg. 



Frequent, and often in abundance. Size: long. 110 (.i & 

 150 ^i, lat. 6,5 II & 9 ft. 



80. Closterium abruptum. W. West. 



Rare. An intermediate form between the type and the var. 

 brevius. Size: long. 107,5 ^i, lat. 14 a. 



