362 XI. DESMiDiACE^ (West). [Staurastrum 



Lund, a smooth under surface to the processes which',have a faintly- 

 recurved apex, as well as a double series of warts along each side. 

 The character and arrangement of these warts, however, its less 

 incurved processes, the different form of its semicells, together with 

 the constantly fusiform vertical view, readily distinguish it. 



23. S. gracile Ralfs in Ann. Nat. Hist. xv. 155-6, t. xi. f. 3 

 (1845); Biit. Desm. 136, t. xxii. f. 12 (1848). 



Var. cyathiforme W. et G. S. West in Trans. Linn. Soc. ser. 2, 

 V. 77, t. ix. f. 2 (1895) ; Journ. Bot. 1897, p. 182. 



PuNGO Andongo. — In stagnis prope Anbilla (Condo) ; March 1857. 

 No. 177. 



Var. pusillum W. et G. S. West in Trans. Linn. Soc. ser. 2, v. 

 77, t. ix. f. 4. 



PuNco Andong •. — In stagnis prope Anbilla (Condo) ; March 1857. 

 No. 177. 



24. S. angolense W. et G. 8. West in Journ. Bot. 1897, p. 183, 

 t. 368, f. 22. 



Pungo Andoxgo. — In stagnis prope Anbilla (Condo) ; March 1857. 

 No. 177. 



The nearest species to this is .S'. hrdcluoprominens Borg. in Vidensk. 

 Medd. f. d. Naturh. Foren., Kjoben. (1890), 47, t. v. f. 52 (1891) ; 

 W. et G. S. West in Trans. Linn. Soc. ser. 2, v. 265, t. xvii. f. 12 

 (1896), from which it differs in the absence of the denticulate apical 

 verrucse and the basal rings of granules, in the presence of the two 

 transverse rows of granules at each side, and in the somewhat shorter 

 and thicker processes. 



25. S. quadridentatum W. et G. S. West in Journ. Bot. 1897 

 p. 183, t. 369, f. 15, 16. 



HuiLLA. — In paludibus exsiccandis ; April 1860. No. 176. Etiam 

 inter Utrieukiriam, Morro de LopoUo ; April 1860. No. 179. 



14. ARTHRODESMUS Ehrenb. (1836). 



1. A. hiatus W. B. Turn, in K. Sv. Vet.-Akad. Handl. Bd. 25, 

 no. 5, 134, t. xi. f. 34 and 40 and t. xii. f. 1 (1893) ; W. et G. S. 

 West in Journ. Bot. 1897, p. 235. 



HuiLLA.— In editis de Morro de LopoUo ; Feb. 1860. No. 192. 



The specimens have the minute spines almost patent and not con- 

 verging ; the apices are not so flattened as in Turner's figures. 



15. GYMNOZYGA Ehrenb. (1840). 



1. G. moniliformis Ehrenb. in Bericht. Verb. Preuss. Akad. 

 Wissenschaft, Berlin, 212 (1840) ; W. et G. S. West I.e. 



Desmidiitm Borreri Ralfs in Ann. Nat. Hist. xi. 375, t. 8, f. 4 

 (1843). Didymopnum Borreri Ralfs, Z.c, xvi. 10 (1845); Brit. 

 Desm. 58-9, t. iii. (1840). Bambusina Brebissonii KUtz. Phyc. 

 Germ. 140 (1845). 



HuiLLA. — Inter Utriculariam, Morro de Lopollo ; April I860. 

 No. 179. 



