COSMAEIUM. 93 



C. Meneghinii forma latiuscula Jacobs. Desm. Danem. 1876, p. 197 ; Hoff 

 in Nordst. Desm. Bornh. 1SS8, p. 197 ; Anderss. Sverig. Chlor. 1890, p. 

 16 ; Borg. Freshw. Alg. Faeroes, 1901, p. 224. 



Semicells witli a slight undulation in the middle of 

 the retuse upper parts of the sides. It has the appear- 

 ance of a reduced C. impressulum in which the undula- 

 tions are not nearly so prominent. 



Length 20-23 //; breadth 15-16'5/x. 



Widely distributed in the British Islands and in continental 

 Europe. 



Yar. nanum \Yille. (PI. LXXII, fig. 34.) 



C. Meneghinii var. nanum Wille, Ferskv. Alg. Xov. Semlj. 1879, p. 43, 

 t. 12, f. 35 ; West, Alg. W. Ireland, 1892, p. 149. 



A small variety with elliptic-hexagonal semicells ; 

 lower parts of sides upwardly diverging, upper parts 

 with a minute median undulation, apex truncate and 

 straight. 



Length 19 p, ; breadth 15 //< ; breadth of isthmus 6 p. ; 

 thickness 11 {JL. 



IBELAXP. Cromasfloun, Kerry ! 



O t) 



Geogr. Distribution.- -Nova Zembla. 



The actual form of the semicell of this variety is nearer that 

 of C. perpusillum than C. Meneghinii, but the depth of the 

 constriction and the form of the vertical view are different. 



110. Cosmarium angulosum Breb. 

 (PI. LXXII, figs. 35, 36.) 



Cosmarium angulosum Breb. Liste Desm. 1856, p. 127, t. 1, f. 17; Cooke, 



Brit. Desm. 1886, p. 93, t. 42, f . 18 ; Eoy & Biss. Scott. Desm. 1894, p. 



42 ; Nordst. Index Desmid. 1896, p. 45 ; G. S. West, Alga-fl. Cainbr. 



1899, p. 216 ; West & G. S. West, Alga-fl. Yorks. 1900, p. 93; Alg. X. 



Ireland, 1902, p. 35 ; G. S. West, Alg. Third Tanganyika Expedit. 1907, 



p. 119. 

 C. Meneghinii Breb. var. angulosum (Breb.) Eabenh. Flor. Europ. Alg. 



Ill, 1868, p. 163 ; Lund. Desm. Siiec. 1871, p. 43 ; Kirchn. Alg. Schles. 



1878, p. 148 ; Wille, Xorges Ferskv. Alg. 1880, p. 30 ; Hansg. Prodr. 



Algenfl. Bohm. 1888, p. 195 ; De Toni, Syll. Alg. 1889, p. 938 ; Hoff in 



Xordst. Desni. Bornh. 1888, p. 198; West, Alg. ~N T . Wales, 1890, p. 289; 



West & G. S. West, Wehv. Afric. Freshw. Alg. 1897, p. 119; Borg. 



Freshw. Alg. Fseroes, 1901, p. 224. 



Cells small, about 1 i times longer than broad (some- 



