194 BRITISH DESMIDIACE.E. 



very slightly pointed and furnished with a terminal 

 granule, and with a series of 6 grannies just within 

 each lateral margin. 



Zygospore unknown. 



Length 39'5^; breadth 33 /u ; breadth of isthmus 

 10 /n ; thickness 20 /<. 



SCOTLAND.- -Rhicoiiich, Sutherland ! 



C. entochondrum should be compared with C. quinarium 

 Lund., C. taxichondrum Lund., and C. Paulense (Borg.) Johns. 

 It is nearest to the last-named species in the possession of the 

 series of large granules within the apical margin, but the 

 rest of the granulation differs considerably. 



O K 



181. Cosmarium Oligogongrus Keinsch. 

 (PL XCI, fig. 8.) 



Cosmarinm Oligogongrus Reinsch, Contrib. Alg. et Fung-. 1875, p. 84, t. 16, 

 f . 6 : De Toni, Syll. Alg. 1889, p. 1041 ; Eoy & Biss. Scott. Desm. 1894, 

 p. 170. 



Ursinella Oligogongrus Kimtze, Kevis. gen. plant. 1891, p. 925. 



Cells rather under medium size, about 1J- times as 

 long as broad, very deeply constricted, sinus narrowly 



linear with a dilated extremity ; semicells transversely 



u n 



oblong-trap eziform, apex rather narrower than the 

 broad base, basal and upper angles obtuse, sides 

 slightly convex and furnished with 4 or 5 equidistant 

 marginal granules, the upper one often being apical in 

 position, apex very broadly truncate and very slightly 

 convex, with 7-9 granules of unequal size within eacli 

 lateral maro-in and with 18-19 granules of variable 



O 7 O 



size irregularly disposed in the centre and surrounded 

 by a considerable smooth area. Side view of semicell 

 circular, with 10-11 unequal marginal granules, apex 

 smooth or nearly so. Vertical view elliptic, ratio of 

 axes about 1 : 1'4, unevenly granulate at the poles and 

 at the middle on each side. 



Zygospore unknown. 



Length 65 /u; breadth o-4-oo/x; breadth of isthmus 

 16/i ; thickness 38 p. 



