STAURASTRUM. 183 



ENGLAND.? Mickle Fell, N. Yorks ! 

 Geocjr. Distribution. Germany (form). Austria (form). 

 Spitsbergen. Greenland. 



This alga is extremely rare in the British Isles. There is only 

 one doubtful record for it from Yorkshire. 



169. Staurastrum monticulosum Breb. 

 (PL CLIV, fig. 8.) 



Binatella monticulosa Breb. in Chev. Micr. 1839, p. 27i'. 



Staurastrum tiwnticulosutn Breb. in Menegh. Synops. Desm. 1840, p. 226 ; 



Ralfs, Brit. Desra. 1848, p. 130, t. 34, f. 9 ; Arch. Suppl. Cat. Desm. 1858, p. 



257, t. 21, f. 1(3 : in Pritch. Inf. 1861, p. 739 ; Rabenh. Krypt,-fl. Sachs. 



1863, p. 192 ; Flor. Europ. Alg. 1868, p. 214 ; Lund. Desm. Suec. 1871, 



p. 65 ; Jacobs. Desm. Danemark, 1875, p. 209 ; Cooke, Brit. Desm. 1887, 



p. 147, t. 5<>. t. 10; De Toni, Syll. Alg. 1889, p. 1156; Comere, Desm. 



de France, 1901, p. 166, t, 12, f.*3 ; Borge, Botan. Xotiser, 1913, p. 50 ; 



Gronblad. Desm. Keuru, 1920, p. 87. 



Phycastrum monticulosum Kiitz. Phyc. Germ. 1845, p. 138. 

 Stephanoxtinthium inonticuh>siun Kiitz. Spec. Alg. 1849, p. 184. 



Cells rather under medium size, very slightly longer 

 than broad, deeply constricted, sinus open and acute ; 

 semicells subtrapeziform, lower lateral margins slightly 

 convex, upper lateral margins distinctly concave, lateral 

 angles truncate with two spines lying in the same vertical 

 plane ; apex of semicell straight or slightly concave, 

 with a pair of short conical processes, tipped with spines, 

 at each upper angle of the semicell (usually only 4 

 of these are visible) ; angles of semicell with several 

 concentric series of small granules. Vertical view 

 usually triangular, sides straight or very slightly convex,, 

 with two spinate projections just within each margin; 

 angles subacute, ending in two spines (one above the 

 other), and with several series of granules. 



Zygospore unknown. 



Length, including spines, 40-57 \L ; breadth, including 

 spines, 35-42 [z ; breadth of isthmus 13-19[ji. 



ENGLAND. --Xear Bowness, Westmoreland (Biss.). 

 ? Cowgill Wold Moss, Widdale Fell, W. Yorks ! Pilmoor, 

 N. Yorks ! Penzance, Cornwall (Ralfs). Dartmoor 

 (Harris). 



