STAURASTRUM. 7 



Austria. Turkey in Europe. Norway. Sweden. Den- 

 mark. Finland. N. Russia. W. Greenland. Japan. 

 Burma. Siam. Australia. United States. 



St. apiculatum is very closely allied to St. dejectum, St. mucro- 

 natum and others, but is readily distinguished from all similar 

 forms by the shape of its semicells, with their nearly straight 

 apices and minute spines projecting vertically upwards. It is 

 quite a common species and is widely distributed. 



The original description of the zygospore given by de Brebisson 

 and copied by Cooke and others is inaccurate, since the zygo- 

 spores have numerous sharp spines, not blunt ones with broad 

 bases. 



45. Staurastrum dejectum Breb. 

 (PI. CXXIX, figs. 9-12.) 



BinateUa dejecta Breb. Alg. Falaise, 1835, p. 269. 



Staurastrum dejectum Breb. in Menegh. Synops. Desm. 1840, p. 227 ; Ralfs, 

 Brit. Desm. 1848, p. 121, t. 20, f. 5 (ex parte) ; Breb. Liste Desm. 1856, 

 p. 142 ; De Bary, Conj. 1858, p. 50, t. 6, f. 25-32 ; Arch, in Pritch. Inf. 

 1861, p. 737 ; Rabenh. Krypt, Fl. Sachs. 1863, p. 189 ; Wood, Freshw. 

 Alg. N. Airier. 1873, p. 148, t. 21, f. 18, t. 13, f. 9 ; Kirchn. Alg. Schles. 

 1878, p. 168 ; Wille, Norges Ferskv. Alg. 1880, p. 40 ; Wolle, Desm. U. S. 

 1884, p. 121, t. 40, f. 7-11, 17-22 (ex parte) ; Lagerh. Bidr. Amerik. Desrn.- 

 fl. 1885, p. 247 ; Cooke, Brit. Desm. 1887, p. 138, t. 49, f. 1 ; De Toni, 

 Syll. Alg. 1889, p. 1137; West, Alg. W. Ireland, 1892, p. 170 ; Alg. Engl. 

 Lake Distr. 1892, p. 18 ; Schmidle, Beitr. Algenfl. Schwarzwald u. Rheineb. 

 1893, p. 107, t, 5, f. 26, 27 (forma) ; Roy & Biss. Scott. Desm. 1894, p. 19 ; 

 Schmidle, Beitr. Alp. Alg. 1895, p. 30, t. 16, f. 30, 31 ; W. & G. S. West, 

 Alga-fl. Yorks. 1901, p. 96 ; Comere, Desm. de France, 1901, p. 161, t. 13, 

 f. 18 ; W. & G. S. West, Alg. N. Ireland, 1902, p. 44 ; Freshw. Alg. Ceylon, 

 1902, p. 175; Scott. Freshw. Plankton, I, 1903, p. 528; Freshw. Alg. 

 Orkneys and Shetlands, 1905, p. 24 ; Coinp. Study Plankton Irish Lakes, 

 1906, p. 86 ; Gutw. Flor. Alg. Mont, Tatr. 1909, p. 470 ; Kaiser, Beitr. Alg. 

 Traunstein Chiemgau, 1914, p. 152. 



St. mucronatum Ralfs in Ann. Mag. Nat. Hist. 1845, p. 152, t. 10, f. 5 (ex 

 parte). 



St. cuspidal um v. dejectum Kiitz. Spec. Alg. 1849, p. 179. 



Didymidium (Staurastrum) erectum Reinsch, Alg. Frank, 1867, p. 157 (ex 

 parte) ; Contr. Alg. Fung. 1875, p. 86, t. 15, f. 8. 



Staurastrum laniatum Delp. Spec. Desm. Subalp. 1877, p. 39, t. 10, f. 25 (in 

 part). 



St. dejectum var. a lunatum Cooke, Brit. Desm. 1887, p. 138, t. 49, f. la. 



St. dejectum f. punctata West, Add. Alg. W. Yorks. II, 1891, p. 247. 



Cells small, about as long as broad (not including the 

 spines), deeply constricted, sinus widely open, acute or 

 obtusely rounded at the apex, often nearly rectangular ; 

 semicells usually more or less triangular in outline, 



