145 



and S. Russia. Faeroes. Central China. Japan. India. 

 Siam. Samoa. New Zealand. Central Africa (var.). 

 E. Africa. United States. W. Indies. Brazil. Uruguay. 

 Patagonia. 



The numerous scattered pyrenoids at once distinguish. Cl. 

 Khrc)il>rr</ii from all other allied species except CL Nalinver- 

 n in mini. It often occurs in abundance, and pure gatherings 

 may sometimes be obtained from amongst other alga3 in 

 stagnant ponds a.ntl ditches, or even l'r< nit slow-running streams. 



The ventral inflation varies much in relative size and pro- 

 minence, and the apices of some specimens are much thicker 

 than those of others. 



The form first mentioned by Borge (Siissw. Chlor. Archang. 

 1894, p. 16, t. 1, f. 11), and since found in Cambridgeshire 

 (G. S. West, Alga-fl. Cambr. 1899, p. 112), is chiefly notable 

 for its relative shortness and for tlie slight curvature of the 

 ventral or inner margin (ride PI. XVII, fig. 3). The curva- 

 ture of the inner margin varies greatly in different specimens, 

 and for this reason the form just mentioned is unworthy of a 

 special varietal name. 



Conjugation appears to take place almost invariably between 

 two individuals which have just separated after division, and 

 in which the younger semicells are but partially developed. 

 Moreover, the semicells do not come apart, but a distinct, 

 though very short, conjugating-tube is protruded from the 

 base of each of the younger semicells. 



25. Closterium Malinvernianum De Not. 



(PL XVII, figs. 5, 6.) 



Closterium Malinvernianum De Not. in Erb. crit. Ital. 1865, no. 1254 [we 

 have not seen this] ; Lund. Desm. Suec. 1871, p. 80 ; De Toni, Syll. 

 Alg. 1889, p. 845 ; Roy & Biss. Scott. Desm. 1894, p. 246 ; Nordst. Index 

 Desm. 1896, p. 163 ; West & G. S. West, Alg. S. England, 1897, p. 481 

 (in part) ; Alga-fl. Yorks. 1900, p. 51 ; Alg. N. Ireland, 1902, p. 23. 



Cl. Ehrenberyii Menegh. b'. ? Malinvernianum Eabenh. Flor. Europ. 

 Algar. Ill, 1868, p. 131. 



Arthrodia Malinvcrniana Kuntze, Revis. gen. plant. 1891, p. 883. 



Closleriuin Cordanum Gutw. Nonn. Alg. Nov. 1896, p. 40, t. 2, f. 19. 



Cells large, 6-7 times longer than their diameter, 

 moderately curved, outer margin 90 110 of arc, 

 median part of inner margin inflated, gently attenuated 

 to the apices, which are obtusely rounded ; cell-wall 

 very finely striated, about 55-65 stria? visible across 



