356 XI. desmidiace^e (West). [Cosrnarium 
47. C. subcostatum Nordst. in Ofv. K. Vet.-Akad. Forh. no. 6, 
37-8, t. xii. f. 13 (1876). 
Forma minor W. et G. S. West in Journ. Bot. xxxiv. 379, t. 
361, f. 15 (1896); xxxv. 122 (1897). 
MOSSAMEDES. — Inter Charas in rivo Caroca pr. Cabo negro; Sept. 
1859. No. 19. 
48. C. alatum Kirchn. in Colin, Kryptogamen -flora von 
Schlesien, Zweit. Bd., 153 (1878) ; W. et G. S. West in Journ. 
Bot. 1897, p. 122. 
Luanda. — In stagnis (Represa de Luiz Gomes) ; Feb. 1858. No. 136. 
LlBONGO.— Ad margines num. Lifune ; Sept. 1858. No. 204. 
Var. suboblongum W. et G. S. West in Journ. Bot. 1897, p. 122. 
Prxtio Axdoxgo. — Adramulos Podostemacearum in rivulis Prassidii 
(Casalale) ; March 1857. No. 105. 
49. C. subtriordinatum W. et G. S. West in Journ. Bot. 1897, 
p. 122, t. 368, f. 11. 
Pungo Andongo. — In stagnis prope Anbilla (Condo) ; March 1857. 
No. 177. 
The nearest species to this is C. triordinatum W. et G. S. West (in 
Trans. Linn. Soo. ser. 2, v. 66, t. vii. f. 27), from which it differs in its 
less wide cells, its rounded and not acute granules, its smooth apex, 
and in its quadrate (not rounded) and fewer central warts. 
50. C callistum W. et G. S. West in Journ. Bot. 1897. p. 172, 
t. 367, f. 13. 
Pungo Andongo. — In stagnis prope Anbilla (Condo) ; March 1857. 
No. 177. 
51. C. colonophorum W. et G. S. West in Journ. Bot. 1897, 
p. 172, t. 367, f. 1. 
Huilla. — In paludibus exsiccandis ; April 1860. No. 176. 
This is a noteworthy species, the large size of the warts and their 
arrangement easily distinguishing it from any other ; the four median 
warts on each side of the vertical view being especially pronounced. 
52. C. bilunatum W. et G. S. West in Journ. Bot. 1897, p. 173, 
t. 367, f. 17. 
Huilla. — In uliginosis editioribus prope Humpata, Empalanca et 
Lopollo ; May 1860. No. 15. 
This characteristic species is nearest in outline to C. prcecehum W. B. 
Turn, and C. indicum W. B. Turn. 
53. C. mucronatum W. et G. S. West in Journ. Bot. 1897, 
p. 173, t. 367, f. 16. 
Huilla. — In paludibus exsiccandis ; April 1860. No. 176- Inter 
Utriculariam, Morro de Lopollo ; April 1860. No. 179. 
This species is distinguished from C. pseudotaxichondrum Nordst. by 
its rounded semi-cells, by the complete absence of granules, and by the 
obloug vertical view. 
54. C. pseudotaxichondrum Nordst in Ofvers K. Vet.-Akad. 
Forh. no. 3, 20, t. ii. f. 5 (1877). 
