BRITISH DtlSMlDIAClvK. 



\V.u,i;s. General in Carnarvonshire (up to 0,000 ft. 

 on Snowdon) ! Merioneth ! 



SCOTLAND. - -Ross, Inverness!, Aberdeen (with 

 zygosp.), Kincardine, Perth!, Stirling, Fife (Hut/ 4' 

 Bissett). Dumfries ! Kirkcudbright ! Ayr (with 

 /ygosp.) ! Caithness ! Sutherland ! General in the 

 Outer Hebrides ! Orkneys ! Shetlands ! 



1 1; ELAND. Donegal ! Mayo ! Gal way ! Kerry ! 

 Londonderry ! Armagh ! Wicklow ! 



(inujf. .Dixti-ilmfioit. France. Germany. Switzer- 

 land. Austria. Galicia. Hungary. Spain. Norway. 

 Sweden. Denmark. Finland. N., S., and Central. 

 Russia. NovaZembla. Greenland. Siberia. Japan. 

 Ceylon. Siam. Sumatra. Java. Samoa. Australia. 

 Central and E. Africa. United States. Brazil. 

 Ecuador. Patagonia. 



This Desinid is not more tlum about luilf the size of CL 

 DiaiiM and is of a stouter aspect. The apices are also rather 

 more acute. Nageli described the cell-wall as being very finely 

 striated, but as we invariably find it perfectly smooth and 

 colourless, we are inclined to believe that he included more 

 than one species in his observations. 



Var. angustum West & G. S. West, (PI. XV, figs. 



1*, 14.) 



Cl. iiiifrnhtm var. <I/M/'<*/ inn West & (_J. S. West, Notes Alg. II, 19UO, p. 29o, 

 t. 'i'1'2, f. 8 ; West & G. S. West, Alya-fi. Yorks. 1900, p. -11) ; Uorgf, 

 Aly. erst. Iteyuell. Exped., II, Dusiuid. l'J03, p. 79. 



( 1 ells a little smaller and narrower than in tlie 

 typical form. 



Distance between apices !H 1 Ol2 ^ ; breadth 7'7/x. 



Ex<; LAND. Pilmoor, N. Yorks! 



<<t'o</i: D-istribution. Brazil. Paraguay. 



i 



17. Closterium Jenneri Ralfs. 



(PI. XV, figs. 23-25.) 



nii Jenneri Kali's, Brit. Desm. 18-18, p. 167, t. 28, f. (i ; Aivli. in 

 Pritch. Iiifus. 18li], p. 74-8; Eabeiih. Flor. Europ. Algar. Ill, 18138, p. 



