COSMARIUM. 141 



sometimes extra large) forming a transverse series 

 across the middle of the semicell, and one large granule 

 immediately above the isthmus. 



Length 32-39 /x, ; breadth 32-39 ^ ; breadth of 

 isthmus 9-14 ^ ; thickness 18-24 p.. 



EXGLAND. Xear Bowness, Westmoreland (Bissett). 



SCOTLAND.- Khiconich, Sutherland! Near View 

 Rock, StrathpefEer, Ross (Roy fy Bissett). 



IRELAND. Xear Grlenties, Donegal ! Ballynahinch, 

 Gal way ! 



Geoc/r. Distribution.- -Norway. United States. 



In Europe this variety has essentially a western and north- 

 western distribution, and appears to be confined to the old 

 formations. Turner's record from " Gror mire, 1ST. Yorks." is 

 very doubtful and requires further confirmation. 



An American variety of C. monomazum (var. tristichum W. 

 & G. S. West, ' Some Desm. U. S.' 1898, p. 305, c. fig.) 

 possesses 9 central granules in three transverse series. 



\ 



144. Cosmarium quadrifarium Lund. 

 (PI. LXXVI, figs. 15-17; PI. LXXVII, figs. 1-3.) 



Cosmarium quadrifarium Lund. Desm. Suec. 1871, p. 32, t. 3, f. 12 ; Wolle. 



Desm. U. S. 1884, p. 87, t. 17, f. 16-18; Cooke, Brit. Desm. 1887, p. 115, 



t. 40, f . 8 ; Boldt, Desmid, Gronland, 1888, p. 23 ; De Toni, Syll. Alg-. 



1889, p. 1022 ; West, Alg-. W. Ireland, 1892, p. 158 ; Eoy & Biss. Scott. 



Desm. 1894, p. 173; Nordst. Index Desm. 1896, p. 218; Schmidle, 



Lappmark Siisswasseralgen, 1898, p. 39 ; Borg-e, Beitriige Alg. Schweden, 



1906, p. 42. 



Ursinella quadrifaria Kuntze, Revis. g*en. plant. 1891, p. 925. 

 Cosmarium quadrifarium forma stellata Gutw. Alg-. Ins. Java, 1902. p. 596, 



t, 38, f. 46. 



Cells rather under medium size, about 1-j times 

 longer than broad, deeply constricted, sinus narrowly 

 linear with a slightly dilated apex ; semicells semi- 

 circular, basal ano'les subrectanffular and only a little 



o o / 



rounded, margin furnished with 15-17 truncate- 

 emarginate warts, those at the basal angles commonly 

 slightly reduced, with a similar series of emarginate 

 warts immediately within the margin ; in the basal part 

 of the semicells just above the isthmus with a pro- 

 minent rounded tumour ornamented with 12-17 



