126 T1T7ITISII DfiSMIPTACE^E. 



IRELAND. Mayo ! Galway ! Kerry ! Donegal ! 



Dublin and Wicklow (Archer). Down! Armagh! 

 Antrim ! 



Geoi/r. Distribution. France. Germany. Austria. 



Poland. Portugal. Norway. Sweden. N. and S. 



o / 



Russia. Faeroes. Ceylon. Australia. United States. 

 Brazil. 



This species is easily distinguished from the succeeding 

 one (Cl. Ulna) by its somewhat greater curvature, its greater 

 attenuation towards the extremities, and its much coarser 

 striolation. It is distinguished from Cl. stnolatum by its 

 proportionately narrower cells and by its fewer and coarser 

 striae. 



The smallest forms we have observed were from Lough 

 Akibbon, Donegal, Ii'elancl : length 190 /n breadth 14 ,u ; 

 breadth of apices o' /u. In other respects they were absolutely 

 typical. 



Var. hibernicum West. (PL XIV, fig. 6.) 



Closterium intermedium var. hibernicum West, New Brit. Froshw. Alg. 



1894, p. 3, t. 1, f . 2 ; West & G. S. West, Alg. S. England, 1897, p. 482 ; 



Alga-fl. Yorks. 1900, p. 55. 

 ? Cl. intermedium a. typicum Klebs, Dcsm. Ostpretiss. t. 2, f. 16. 



A rather long variety with the median part of the 

 cell straight and the apical portions somewhat suddenly 

 incurved ; with 9 visible striae, which are rather 

 stronger than in the typical form. 



Length 290 p; breadth 19/x. 



ENGLAND. --Terrington, N. Yorks ! Puttenham 

 Common and near Chapel Wood, Surrey ! 



IRKLAND. Westport, Mayo ! 



Var. sculp turn Racib. 



Closterium iiiternicilhnn var. sculptum Eacib. Desm. Nowe, 1889, p. 75, t. 7, 

 f. 19. 



A variety 15-17 times longer than the diameter, 

 commonly with 9 visible stride, each being composed 

 of a series of oblong granules (2-3 //, in length). 



Length 456-512 p ; breadth 30-32 ^ ; breadth of 

 apices about 1 5 //,. 



Distribution.- -Bohemia. 



