80 WELWITSCH's AFRICAN FRESHWATER ALGiE. 



Pungo Andongo. In stagnis prope Anbilla (Condo) ; March 

 1857. No. 177. 



This species can be compared with P. subcoronidation (W. B. 

 Turn.) West, and P. conjimctum (W. B. Turn.). 



2. P. Ehrenbergii (Breb.) De Bary, Couj. 75 (1858). Docidmm 

 Ehrenbeniii Breb. (1844) ; Ealfs, Brit. Desm. 157, t. xxvi. f. 4 (1848). 

 Long. 408 n ; lat. bas. semicell. 22 /x, apic. 16 /x. 



Pungo Andongo. In stagnis prope Anbilla (Condo) ; March 

 1857. No. 177. 



3. P. MAXIMUM (Eeinsch) Lund, in Acta Pi. Soc. Sclent. Ups. 

 ser. 3, viii. no. ii. 89 (1871). Ihciilium maximum Eeinsch in 

 Abhandl. Si'nckenb. Naturforsch. Gesellsch. vi. 140, t. xx. C ii. f. 1-2 

 (1866-7); in AbhancU. Naturhist. Gesellsch. zu Nurnbenj, iii. 184, 

 t. xii. f. 4 (1866). Long. 762-779 /x; lat. bas. semicell. 43-44 fx, 

 med. semicell. 38-5-40 /x, apic. 25-27 fj-. 



Libongo. Ad raargines flum. Lifune ; Sept. 1858. No. 204. 

 The shorter semicells (which are sometimes only 175 ^ in 

 length) have only one basal inflation ; the longer ones have two. 



7. Ichthyocercus, gen.n. 

 Cellalte cylindrico-fasiformes, subelongatte, ad medium leviter 

 constrictfe; a f route visae lateribus subparallelis, apicibus basibusque 

 semicellularum in latitudine subaequalibus (uonnunquam apicibus 

 paullo angustioribus vel paullo latioribus), depressione lata minime 

 profunda ad apices per latitudinem totam, spina brevi leviter di- 

 vergente ad angulum uuumquemque iastractfe ; a vertice vis^e 

 subcirculares. 



1. I. angolensis, sp. unica. (tab. 368, figs. 26-31). I. sub- 



parvum, diametro 3-5-plo longior (sine spinis) ; semicelluliB a fronte 



visffi oblougte, lateribus leviter convexis, infra apices leviter dilatatos 



interdum angustatje ; a latere visas elongato-ovata?, apice acute 



rotundato cum spina brevi instrncto ; membrana tenuissima delicate 



punctata vel punctato-scrobiculata ; cet. charact. ut in genere. 



Zygosporas globosae vel late elliptical; membrana crassa, glabra, 



bilamellata, lamella interiori scrobiculata. 



Long, (sine spin.) 46 ; 



Lat. bas. semicell. 15 ; 



Lat. apic. semicell, 12-5; 



Lat. isthm. . . 18-5; 



Long. spin. . . 1-6; 



Diara. zygosp. 21-33-5 /x. 



Huilla. In uliginosis editioribus prope Humpata, Empalanca 



et Lopollo, plagas spongiosas unacura Eriocauloneis, Xyridibus et 



Utriculariis constituens ; May 1860. No. 15. In graminosis palu- 



dosis juxta rivulum de Lopollo ; April 1860. No. 180, Morro de 



Lopollo ; May 1860. No. 182. 



This genus seems to be near Tetmemorus and Euastrum. It 

 resembles the former in its elongate form, in being but slightly 

 constricted in the middle, and in possessing a circular (or very 

 nearly circular) vertical view; it differs from it, however, in the 



