Zygnema] x. eygnkmai k.k (West). 
3. Zygnematis ap. W. el G. B. West, l.o. 
I'i \(.u Anhonco. Cum Sn/1,,,1, mat. in IVdra SoQgue . April 1867 
No. 153. 
5. SPIROGYRA Link, 1820). 
1. Spirogyrae sp. \\ . el G. 8. Wesl in Journ. Bot. 1897, p. 10. 
Hi ii. i. a. [nter alias algae in nliginosis editioribus props Eumpata, 
Empalanca el Lopollo; May 1860. N". 15. Not in soffioient quantity 
for absolute specific determination. 
2. Spirogyrae sp. W. et <!. S. West, l.c. 
Pungo Andongo. Enter Batrachoepermum nigrescent in Hum. 
Cuanza ; .March L857. No. 104. Ad rupes humidas juxta 
Cuanza : March L857. No. 156. 
<; .mi ngo Ai.in. Preq. in semistagaantibns ad ripas Etivi Qaiapoze 
Caminbo (road) para Mussc-ngne : Sept. 1 s;,.">. So. 207. 
3. Spirogyrae sp. W. el G. 8. West, l.c. 
Pungo Andongo. a . I ramulos Podostemacearum (Tristicha) in 
rivulis Pnssidii ; March L857. No. 109. Nothing can be made out of 
the specimens with any precision. 
I. S. neglecta Kiitz. Species Algar. Ml (1849) j Rabenh. I-'I. 
Europ. Algar. in. 248; Petit, Spirog. de Paris. 26, t. ix. !'. 1 5. 
Zygnema neglecta Bass. Brit. Freshw. Alg. 142, t. 23, f. I 2 
(1845). 
Var. ternata W. el <;. S. Wesl in Journ. Bot. L&97, p. 11. 
S. ternata Ripaii in Bull. So,-. Bot. Fr. \.\iii. 162(1876) ; Petil 
l.c., 26, t, viii. f. 4-7. 
HuiLLA. — Frequentissima post pluv. autumnal, ad margines rivu- 
lorum ]>rope Lopollo : April I860. No. 185. 
5. Spirogyrae sp. W. et G. S. West, l.c. 
Ptjngo Andongo. — Inter Batrachospt rmum nigrescens in riv. Cuanza : 
March L857. No. 104. 
6. S. angolensis WVlw. es W. ei <;. 8. Wesl in Journ. Bol 
1897, p. 41. 
Loanda. — Cum Microspora fontbiali in aquis Btagnorum puris 
(Cazimba) urbis Loanda: June lSf>8. No. 124. In Btagnis artifici 
alibus (Repress de Manuel Pereira van Buiien) oirca Loandam 
July 1864. No. 193. Etiam No. 103. 
The very dark-coloured conjugating filaments and the form of 
the zygospores characterise this species. S. arcta (Ag.) Kut/. , to 
which No. 193 was referred by Welwitsch, is a much smaller plain 
with but one chromatophore, and the conjugating filaments are not 
dark-coloured. 
7. S. Welwitschii W. et G. 8. Wesl in Journ. Bot. 1897, p. II. 
Loanda. — Sp. denso agmine crescens, aubeoularum amoeniss. ririd. 
ad instar aquis innatans ; in Btagnis artificialibus oirca Loandam 
(Repress de M. Pereira van Buiien) c. S.angolensi Welw. ; Ju 
No. 103. 
This species approaches S. decimina (Mull.) Kut/. (to which 
Welwitsch had referred it) and S. neglecta (Haas I KM it differs 
from the former in its much greater thickness, ahortei cells, and 
