EUASTRUM. 11 



one just above the isthmus and two others immediately 

 above it, forming a triangle with it ; upper half of semi- 

 cell destitute of protuberances. Side view of semicell 

 with the lower third subrectangular and upper third 

 elongate-pyramidate, protuberances of lower part of 

 semicell showing distinctly at the sides near the base : 



O i 



apices dilated, slightly retuse and with rounded angles ; 

 upper lateral lobe widely emarginate. Vertical view 

 elliptic, with four prominent protuberances at each 

 side, and a fifth showing between and below the two 

 central ones ; upper lateral lobes widely emarginate ; 

 polar lobe oblong-rectangular, with retuse sides, emar- 

 ginate poles, and rounded angles. Cell-wall coarsely 

 punctate, angles and protuberances frequently scro- 

 biculate (and with a slightly roughened surface). 



Zygospore unknown. 



Length 130-153 p, ; breadth 63-77 JJL ; breadth of 

 isthmus 20-24 /x; thickness 46 50 /x. 



ENGLAND. Angle Tarn, Cumberland ! Elter Water ! , 

 near Bowness (Bissett), Loughrigg (Bennett), West- 

 moreland. Hawkshead, Lancashire ! Xew Forest, 

 Hants (Bennett). 



WALES. Capel Curig and Llyn-y-cwni-ffynon !, Pen- 

 y-gwrvd (Ro//), Carnarvonshire. Dolo'elly, Merioneth 

 (Rcdfs). 



SCOTLAND. Sutherland ! Ross ! , Aberdeen, Kincar- 

 dine, Forfar, Perth, Argyll (Roij $ Bissett). Lewis, 

 Harris (often abundant), and X. L^ist, Outer Hebrides ! 



IRELAND.- -Dungloe, Donegal ! Eoundstone, Bally - 

 nahinch, Loughs Aunierin and Shindilla, Galwav ! Xear 



o . 



Castletown and Carrantuohill, Kerry ! Dublin and 



, 



Wicklow (Archer). 



Geogr. Distribution.- -France. Germany. Galicia in 

 Austria. Xorwav. Sweden. Faeroes. Laiited States. 



t/ 



E. pinnatum is a very characteristic species,, and in certain 

 parts of the west of Scotland and Ireland it occurs in abun- 

 dance. The figures given by Ralfs (Lc. t. 13, f. 1) are not 

 good. Ralfs' fig. 1 a gives a correct idea of the outline of the 

 average form, but fie - s. 1 b, c, and d are incorrectlv drawn, 



Cj * < > * * *J S 



