122 BRITISH DESMIDIACEJE. 



SECTION A. 

 Cells subcjlindrical, granulate or verrucose. 



* Seniicells uniformly granulate. 1 . St. Meriani. 



* Seniicells granulate in the upper part (or more rarely with 

 very short minute spines), with a basal ring of 

 verrucse. 

 t Three apical lobes of semi cells spreading horizontally. 



2. St. capitulum. 

 ft Three apical lobes of semicells upwardly divergent. 



3. St. pileolatum. 



*** Seniicells verrucose both in the upper part and at the 

 base. 



4. St. rlialtdopliorum. 



1. Staurastrum Meriani Reinsch. 

 (PL CXVIII, figs. 4-6.) 



Staurastrum Meriani Eeinsch, Spec. Gen. Alg. 1867, p. 125, t. 23 D I, 

 fig. 1-11 ; Nordst. Norges Desm. 1873, p. 29 ; Wolle, Desm. U. S., 

 1884, p. 132, t. 46, f. 17-19; Nordst. Desmid. Gronl. 1885, p. 10 ; Cooke, 

 Brit. Desm. 1887, p. 161, t. 55, f. 2 ; West, Desm. Mass. 1889, t. 3, f. 22 ; 

 Alg. N. Yorks. 1889, p. 293; De Toni, Syll. Alg. 1889, p. 1192; West, 

 Alg. N. Wales, 1890, p. 294 ; Hansg. Prodr. Algenfl. Bohni. ed. germ. 

 II, 1892, p. 259; West, Alg. W. Ireland, 1892, p. 179; Alg. Engl. Lake 

 Distr. 1892, p. 732 ; Eoy & Biss. Scott. Desm. 1893, p. 22 (sep. ) ; Nordst. 

 Index Desm. 1896, p. 169 ; W. & G. S. West, Alg. S. England, 1897, 

 p. 494; Liitkem. Desm. Millstattersees, 1900, p. 80; W. & G. S. West, 

 Alga-fl. Yorks. 1901, p. 103 ; Borg. Freshw. Alg. Faeroes, 1901, p. 231 ; 

 W. & G. S. West, Alg. N. Ireland, 1902, p. 51 ; Larsen, Freshw. Alg. 

 E. Greenland, 1904, p. 98 ; W. G. S. West, Freshw^Alg. Orkneys and 

 Shetlands, 1905, p. 25'; Teodoresco,- Mater, flor. alg. Eouman. 1907, p. 

 185 ; Larsen, Ferskvandsalg. Vest-Gronl. 1907, p. 350. 



Didymidium (Staurastrum} Meriani Eeinsch. Algenfl. Frank. 1867, p. 160, 

 t. 12, f. 1. 



Oalocylindrus cylindricus (Ealfs) Eacib. var. hcxagona Eacib. in Spraw. 

 Kom. fizyjogr. Akad. Um. Krakow, xix, 1884, p. 9. 



Staurastrum hexagonum Eacib. Nonn. Desm. Polon. 1885, p. 85, t. 12, f. 3. 



Dysphinctium Ralfsii (Klitz.) Hansg. var. hexagonum Schmidle, Alg. 

 Bern. Alp. 1894, p. 92. 



Cosmarium pseudoralfsii Migula in Flora von Deutschland, Osterreich 

 und der Schweiz. Bd. 5 (Desmidiacese in parts 29-36), 1906, p. 423. 



Staurastrum! Meriani forma constrict a Teodoresco, Mater, flor. alg. 

 Eouman. 19U7, p. 185. 



Cells rather small, about twice as long as broad, 

 slightly constricted, sinus a small indentation ; semi- 

 cells trapeziform-rectangular or trapeziform- quadrate. 



