80 1HUTLSH n 



ENGLAND.- -Puttenham Common, Surrey ! 



IRELAND. Near Glenties, Lousflis Anna and Nacallv, 



O i/ 7 



Donegal ! Lough Derryadd, Armagh ! 



Geoc/r. Distribution. --Silesia in Austria. United 

 States. Madagascar. 



o 



The typical form of C. Sinostegos does not appear to have 

 been observed since its original discovery by Schaarschmidt, 

 but Grut win ski's var. obtusius has a wide geographical distri- 

 bution. It differs principally in the lower angles of the 

 semicells being much less produced. It should be compared 

 with C. polygonum, C. geometrician, and C. adoxum. 



The form of 0. Sinostegos described and figured by Johnson 

 (< Bare Desm. U. S./ II, 1895, p. 294, t. 240, f. 29) must be 

 referred to var. obtusius. 



101. Cosmarium abruptum Lund. 

 (PL LXXII, 'figs. 1, 2.) 



Cosmarium abruptum Lund. Desm. Suec. 1871, p. 43, t. 2, f. 22 ; De Toni, 

 Syll. Alg. 1889, p. 947 ; Eoy & Biss. Scott. Desm. 1894, p. 41 ; Nordst. 

 Index Desm. 1896, p. 36 ; West & G-. S. West, Alg. S. England, 1897, 

 p. 489 ; Alga-fl. Yorks. 1900, p. 92. 



Ursinella abrupt a Kiintze, Revis. gen. plant. 1891, p. 894. 



Cells minute, a little longer than broad, deeply con- 

 stricted, sinus narrow and linear ; semicells trans- 

 versely subrectangular, apex produced and truncate, 

 sides slightly retuse, both inferior and superior angles 

 very minutely truncate, on each side between the 

 superior angles and the apex narrowly retuse. Side 

 view of semicell subcircular, with a median papilla on 

 each side. Vertical view elliptic, with a papilla at the 

 middle on each side, ratio of axes (without papilla) 

 1 : 1*7. Cell-wall smooth. Chloroplast axile with a 

 central pyrenoid. 



Zygospore unknown. 



Length 18-20 /x; breadth 15'5-lS//,; breadth of 

 isthmus 4'5-5'5 JJL; thickness 12 p.. 



ENGLAND.- -Mickle Fell, N. Yorks ! Leicestershire 

 (Roi/). Enbridge Lake, Hants (Roy). Halgavor Moor, 

 Cornwall ! 



SCOTLAND. Nairn ; Howforcl, Alford, Birsemore 



