362 xi. desmidiac e.k (West). [Siiiumstruifc 
Luud. 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); Brit. 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. 
Pongo Andong — In stagnis prope Anbilla (Condo) ; March 1857. 
No. 177- 
24. S. angolense W. et G. S. West in Journ. Bot. 1897, p. 183, 
t. 368, f. 22. 
PUNGO ANDONGO. — In stagnis prope Anbilla (Condo) ; March 1857. 
No. 177. 
The nearest species to this is S. brachioprominetis 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. 2G5, t. xvii. f. 12 
(1896), from which it differs in the absence of the denticulate apical 
verruca? 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. 8. West in Journ. Bot. 1897 
p. 183, t. 369, f. 15, 16. 
Htjilla. — In paludibus exsiccandis ; April 1860. No. 176. Etiam 
inter Utriculariam, Morro de Lopollo ; April 1860. No. 179 
14. ARTHRODESMUS Ehrenb. (1836). 
1. A. hiatus W. B. Turn, in K. Sv. Vet.-Akad. Hand]. 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 Lopollo ; 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. GYMN0ZYGA Ehrenb. (1840). 
1. G. moniliformis Ehrenb. in Bericht. Verb. Preuss. Akad. 
Wissenschaft, Berlin, 212 (1840); W. et G. S. West I.e. 
Desmidium Bon-eri Ralfs in Ann. Nat. Hist. xi. 375, t. 8, f. 4 
(1843). Didymoprium Borreri Ralfs, I.e., xvi. 10 (1845); Brit. 
Desm. 58-9, t. iii. (1840). Bambusina Brebissonii Kiitz. Phyc. 
Germ. 140 (1845). 
Hi: iLhA.— Inter Utriculariam, Morro de Lopollo; April I860. 
No. 179. 
