235 



WELWITSCH'S AFBICAN FRESHWATER ALG^E. 

 By W. West, F.L.S., and G. S. West, A.R.C.S. 



(Plates 365-369.) 

 (Continued from p. 183.) 



14. Arthrodesmus Ehrenb. (1836). 



1. A. HIATUS W. B. Turn, in K. 8v. Vet.-Akad. llancU. Bel. 25, 

 no. 5, 134, t. xi. f..31 & 40 & t. xii. f. 1 (1893j. Long. 25-26 /x ; 

 lat. sine acul. 28-29 /'., cum. acul. 31-32-5 /x; lat. istlim. 9 /j. ; 

 crass. 11 //.. 



Huilla. Lopollo ; Febr. 18G0. No. 192. 



The specimens have the minute spines ahnost patent and not 

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



15. Gymnozyga Ehrenb. (1840). 



1. G, MONILIFORMIS Ehrenb. in Bericht. Verh. Preuss. Akad. 

 Wissenschaft. Berlin, 212 (1840). Desmidium Borreri Ralfs in Ann. 

 Nat. Hist. xi. 375, t. 8, f. 4 (1843). Didi/mopriiim Borreri Ralfs, 

 I.e. xvi. 10 (1845); Brit. Desm. 58-9, t. iii. (1840). Bamhudna 

 Brebissonii Kiitz. Phijc. Germ. 140 (1845). Long. cell. 28-30 /x ; 

 lat. cell. 16-18 /x. 



Huilla. Inter Utriculariam, Morro de Lopollo ; April 1860. 

 No. 179. 



XIT. — Vaucheriace^. 

 1. VaucheriaDC. (1803). 



1. V. SEssiLis (Vauch.) DC. Blor. Fr. ii. 63 (1805); Cooke, 

 Brit. Frcshw. Ah/. 123, t. 46, f. 1-20 & t. 48, f. 1-5. Kctmi>erma 

 sessilis Vauch. Hist. Conferv. 31, t. ii. f. 7 (1803). Crass, fil. veget. 

 69-75 /x; lat. oospor. 79 /x, altit. 90 /x. 



Golungo Alto. In I'ossis exsiccatis adhuc humidis in Varzea 

 pone doin. Isidni ; Aug. and Sept. 1855. No. 132. Covers in Aug. 

 and Sept. all the half-dried-up ditches of the plain. 



Var. MONOGYNA var. u. Viir. oogoniis semper solitariis, ovatis 

 et leviter obliquis vel ovato-rostratis. Crass, fil. veget. 46-77 /x ; 

 lat. oospor. 67-103 /x ; crass, membr. oospor. 4-8-5'8 /x. 



Golungo Alto. Ad margines stagnorum rivi Ciiango ; Aug. 1857, 

 No. 155. 



XIII. — Hydrogastrace.e. 

 1. BoTRYDiuM Wallr. (1815). 



1. B. GRANULATUM (L.) Grsv. Al<j. Jlrit. 196, t. xix. (1830): 

 Cooke, Jirit. Fresltw. Ahj. 114, t. 45. Ulra tiranidata L. ,S>. Pi. 

 1633. Ihjdrotjastruin (iranulatum Desv. 



Var. .EQuiNocTiALE, var. n. Var. minor, circiter tertia pars 

 dimensionis planta' typicie ; plantis densissime aggregatis. 



Loanda. Non infret^ucns in territor. Loandensis terris humidis 

 argillaceo-arenosis, latis plagas imo urbis ipsius plateas etc. ob- 

 tegeus ; mox post pluvias copiosas nascens, citoque tempore sicco 

 disparens. Ad fin. Apr. 1854. No. 199. 



