EUASTRUM. 29 



stout, abruptly-sharp-pointed spines," whereas we find them 

 covered with short, stout, blunt papilla?. 



The undulation at the sides of the semicells varies very 

 much, so that we find it impossible to clearly define the " var. 

 sublobatum" of Delponte. 



Yar. pyxidatum Delp. (PL XXXVI, figs. 14, 15.) 



E. ansatum var. pyxidatum Delp. Desm. subalp. 1873, p. 103, t. 6, f. 32-34; 

 De Toni, Syll. Alg. 1889, p. 1097. 



Semicells almost three-lobed owino- to the 



O 



development of the undulation above the basal angles, 

 upper portion of lateral margins deeply sinuate, "polar 

 lobe " subquadrate with rounded angles. 



Length 65-86 p ; breadth 33-42 p. ; breadth of 

 isthmus 12-14 ^t; thickness 22-27 /x. 



SCOTLAND. " Common" (Roy $ Bissett). AYe find it 

 very rare ! 



IEELAXD. G-alwav ! 



b 



Geogr. Distribution. Poland. Italy. 



15. Euastrum obesum Josh. 

 (PI. XXXVI, figs. 16, 17.) 



Euastrum obesum Josh. Burmese Desm. 1886, p. 638, t. 23, f. 19, 20; De 

 Toni, Syll. Alg. 1889, p. 184 ; Xordst. Index Desm. 1896, p. 184 ; West 

 & G. S. West, Alga-fl. Yorks. 1900, p. 62. 



Helierella obesa Kuntze, Revis. gen. plant. 1891, p. 899. 



Cells of medium size, about twice as long as broad, 

 deeply constricted, sinus narrowly linear; semicells 

 pyramidate, with broadly-rounded basal angles, lower 

 part of lateral margins convex, upper part slightly 

 concave, apex widely subtruncate with rounded angles 

 having a narrow median incision. Side view of semi- 

 cell ovate-pyramidate, apex rounded. Vertical view 

 broadly elliptical, lateral margins very slightly 

 biundulate. Cell- wall smooth. 



Zygospore unknown. 



Length 50-111^; breadth 30-59 /i; breadth of 

 apex 17-28 JJL; breadth of isthmus 9-21 p.. 



EXGLAXD. Mossdale Moor, Widdale Fell, X. Yorks 

 (large specimens) ! 



