MICRASTEEIAS. 119 



and lateral lobes. Side view of semicell ovate-pyra- 

 midate, with, a small granulate basal inflation, and 

 showing the asymmetrical apical processes. Vertical 

 view rhomboid-fusiform, with a small granulate pro- 

 tuberance at the middle on each side, poles produced 

 and truncate-denticulate, polar lobe showing the asym- 

 metrical disposition of the apical processes. 



Zygospore unknown. 



Length 125-160 p.; breadth 100-145 /*; breadth 

 (maximum) of polar lobe 63-75 p.; breadth of isthmus 

 17-22-5 p.. 



EXGLAND. Bowness and Deepdale, Westmoreland ! 

 Mickle Fell, N. Yorks ! Askwith Moor, and Cocket 

 Moss near Grilles wick, W. Yorks ! Warwickshire 



oo ' 



( Wills). Near Chapel Wood, Surrey ! Sussex (Ealfs). 



WALES. Capel Curig ! (Gooke fy Wills), Snowdon !, 

 Carnarvonshire. Dolgelly, Merionethshire (Ealfs). 



SCOTLAND. Scotston Moor, Powlair, Birsemore, Slew- 

 drum, Morven, Lochnagar, and Corrie of Loch Ceaii- 

 mhor, Aberdeen; Glen Dye and Clochnaben, Kincar- 

 dine; Lundie Bog near Menmuir, Forfar(7ic^/ SfBissett). 

 Glen Sliee and Glas Maol, Perth ! Plankton of Loch 

 Doon, Ayr ! Loch Ness ! (./. Murray), and plankton 

 of Lochs Shiel and na Cloiche Sgoilt !, Inverness. 



IRELAND. Dublin and Wicklow (Archer). Carrantu- 

 ohill, Kerry. 



Geogr. Distribution. France. Germany. Galicia. 

 Hungary. Norway. Sweden. Bornholm. Poland. 

 Greenland. N. India. E. Africa. United States. 



M. Americana is principally characterized by the form of 

 its lateral lobes. It lias a wide distribution in the British 

 Islands, but is an uncommon species. 



Yar. recta Wolle. (PI. LIV, fig. 4). 



M . Americana var. recta Wolle in Bull. Torr. Bot. Club, 1876, p. 122 ; 

 1881, t. 6, f. 2; Desm. U.S. 1884, p. 112, t. 32, f. 2; West, Alg. N. 

 Yorks. 1889, t. 291, f. 13, Alg. N. Wales, 1890, p. 286. 



Extremities of lateral lobes and polar lobe rounded, 

 not denticulate; apex of polar lobe almost straight 



