82 welwitsch's African freshwater alg.e. 



et LopoUo, plagas spongiosas uuacum Eriocauloneis, Xyridibus et 

 Utriculariis constituens; May 1860. No. 15. 



The front view of this species is considerably different from that 

 of E. intermediuw Cleve, a depressed form of which it somewhat 

 resembles at first sight, and the vertical and lateral view^s readily 

 distinguish it from all Euastra of this class. 



Var. cLAusuM (tab. 3G6, fig. 13). Var. minor, sinu linear! ex- 

 trorsum non aperto; membrana punctata. Long. 38"5/x; lat. 25 /x; 

 lat. apic. 22 /x ; lat. constrict, sub apic. 13 /x ; lat. isthm. 7*5 /x ; 

 crass. 15 /x. 



Huilla. In graminosis paladosis juxta rivulam de LopoUo; 

 April 18G0. No. 180. 



2. E. holoscherum, sp. n. (tab. 3G6, fig. 11). E. submediocre, 

 duplo longius quam latius, profundissime constrictum, sinu angusto- 

 lineari extremo ampliato ; semicellula? quadrato-ovatte, angulis ba- 

 salibus rectangulares, lateribus parallelis sed gradatim (vel potius 

 siibito) apicem versus angustatis, iucisura profunda lineari mediana 

 ad apicem ; a latere visfe elongato-ovatte lateribus retusis ; mem- 

 brana glabra. Long. 51 /x ; lat. 25 /x; lat. isthm. 8 /x; crass. 15 /x. 



Huilla. Inter Micros/wram ahhreviatam et Balrachospermum. 

 huillense, in rivulis prope Lopollo ; May 1860. No. 187. 



3. E, ANSATUM Ehrenb. Abhaiidl. Akad. Wisseitschaft. Beiiin 

 (1831), 82 (1832) ; lufas. 162, t. xii. f. vi. 2 (1838) ; Ralfs, Brit. Des,n. 

 85, t. xiv. f. 2. Long. 81 /x ; lat. 36 /x, apic. 17 /x. 



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

 1857. No. 177. 



4. E. huillense, sp. n, (tab. 366, figs. 15, 16). E. submediocre, 

 2i-plo lougius quam latius, profunde constrictum, sinu angusto- 

 lineari extremo subampliato ; semicelluUe anguste truncato-pyra- 

 midata:!, angulis basalibus leviter rotuudatis, lateribus subrectis vel 

 leviter concavis elevatione mediana parva incrassata et leviter 

 emarginata, angulis superioribus oblique subtruncatis et incrassatis, 

 apicibus leviter convexis (nonnumquara subrectis) incisura profunde 

 lineari in medio, ad basin juxta supra isthmum tumore prominenti ; 

 a vertice vis;^ oblougo-elliptica\ tumore truncato-emarginato promi- 

 nenti ad medium utrobique; a latere visie oblong;^ angulis basalibus 

 rectangiilaribus et angulis apicalibus rotundatis ; membrana dense 

 et delicate punctata, cum scrobiculis paucis sparsis (circiter 6-9 in 

 semicellula unaquaque) plerumque intra marginem uinimquemque 

 aggregatis et a latere visis distinctis. Long. 43-57 /x; lat. 20-26 /x ; 

 lat. apic. 13-5-16 /x ; lat. islhm. 7'5-!J"5 /x ; crass. 18-19 /x. 



Huilla. In uliginosis editioribus prope Humpata, Empalanca 

 et LopoUo; May 1860. No. 15. Etiam in paludibus exsiccandis; 

 AprU 1860. No. 176. 



E. ansatuin Elirenb. var. tnniiduni. Brerg. (in Videnah. Medd. 

 Natuili. Foren. Kjobcii. (1890), 33, t. iii. f. 15) is somewhat near 

 this species in outline, but its dimensions and other characters are 

 very different. 



5. E. siNuosuji Leuorm. (1845) ; Ralfs, /. c. 85, t. xiii. f. 5a,b,c 

 (1848). 



