OLOSTE1UUM. 169 



44. Closterium Lundellii Lagerli. 

 (PL XXI, fig. 17.) 



Closterium gracile Lund. Desm. Suec. 1871, p. Mi. t. ">, f. 15. 



Cl. Lundellii Lagerh. Bidr. Sverig. Algfl. 1883, p. 53; DC Toui, Syll. Alg. 



1SS9, p. 818; Eoy & Bias. Scott. Desm. 1894, p. 240; Nordst. Index 



Desm. 1890, p. 160. 

 Aftkrodia Lundellii Kuntze, Kevis. gen. plant. 1891, p. 883. 



Vegetative cells exactly similar to those of (!. </i-<i<-Hr 

 Brub. Zygospore subquadrate with rounded angles, 

 each angle furnished with a long spine which fits into 

 the base of an empty semicell. 



Length of zygospore without spines 28-30 p, breadth 

 22 p; length of spines 16-17*5 p. 



ENGLAND. Enbridge Lake, Hants. (Roy). 



WALES. Bettws-y-coed, Carnarvonshire (Roi/). 



SCOTLAND. Loch Inver, Sutherland ; Fyvie, near 

 Alford, and S.AV. of Loch Kiiinord, Aberdeen (Rot/). 



Geoijr. Distribution. Sweden. 



Roy is the only observer who lias recorded this Desmid as 

 British, and he has never mentioned the occurrence of zyg'o- 

 spores. As the vegetative cells are indistinguishable from 

 those of Cl. gracile, these records must be regarded as doubt- 

 ful. We give a copy of LundelPs figure of the zygospore 

 (PI. XXI, fig. 17). 



45. Closterium attenuatum Ehrenb. 

 (PI. XXII, figs. 1-3.) 



Closterium attenuatum Ehrenb. Infus. 1838, p. 94, t. 6, f. iv ; Menegh. 

 Synops. Desm. 1840, p. 233 ; Kali's, Brit. Desm. 1848, p. 169, t. 29, f. 5 

 (char, amend.) ; Arch, in Pritch. Infus. 1801, p. 749, t. 3, f. 43 ; Kabenh. 

 Flor. Europ. Algar. Ill, 18(38, p. 130 ; Kirchn. Alg. Schles. 1878, p. 138 ; 

 Wolle, Desm. U.S. 1884, p. 41, t. 8, f . 5 ; Cooke, Brit. Desm. 188(3, p. 32, 

 t. 14, f. 1 (figure very bad) ; De Toni, Syll. Alg. 1889, p. Mi 9 : Liitkrm. 

 Desm. Attersees, 1893, p. 542 ; Eoy & Biss. Scott. Desm. 1894, p. 24ii ; 

 Nordst. Index Desm. 189G, p. 54; West & G. S. West, Alg. S. England, 

 1897, p. 482; Alga-fl. Yorks. 1900, p. 55; Alg. N. Ireland, 1902, p. 24. 



Cl. candianum Delp. Desm. subalp. 1877, p. 104, t. 17, f. 7-10. [Cl. 

 attenuatum Ralfs, btit not Ehrenb., according to Delponte.] 



Arthrodia attenuata Kuutze, Kevis. gen. plant. 1891, p. 883. 



A. candiana Kuntze, 1. c. 



Cells large, 11-14 times longer than their diameter, 

 slightly curved, outer margin about 45 of arc, inner 



