282 



DR. G. DICKIE ON" ALQiE FROM LAKE NTASSA. 



Ctlindrospermum: :ntassje, n. sp. Trichomatibus rectis, in 

 stratum cseruleum intricatis, articulis ellipticis, diaiaetro ('03005) 



duplo longioribus ; sporis ? 



It communicates to water a blue solution with dull-red fluores- 



cence. 



Diatomace.e. 



Cyclotella rotula, Ktz. 

 C. operculata, Ktz. 

 Epithemia ventricosa, Ktz. 

 E. zebra, Ehb. 



Epithemia alpestris, Sm. 

 E. sorex, Ktz. 

 E. turgida, Ktz. 



Epithemia clayata, n. sp. Medio- 

 cris, plus minusve clavata, apicibus 

 rotundato-obtusis, costis validis sub- 

 parallelis, 15 in '001 ; latere superiore 

 (dorso) convexo, inferiore subrecto. 

 Long. =-00l--007 poll. 



More or less plentiful on most of 

 the Phsenogams already noted, but 

 especially so on the Spirogyra. The 

 clavate form at once distinguishes it 

 from any known species ; at first 

 sight it has a resemblance to Stiri- 

 rella (see woodcut). The strise proper 

 are not represented here; they are 30 

 in -001. 



Eunotia tridentula, Ehrb. 

 Himantidium pectinale, Ktz. 



Cocconema cymbiforme, Ehb. 

 C. cistula, Hemp. 

 Amphora ovalis, Ktz. 

 Encyonema prostratum, Berk. 

 Cocconeis placentula, Ehb. 



Fragilaria undata, Sm. 

 Synedra ulna, Ehb. 

 S. acus, Ktz. 

 S. biceps, Ktz. 



Navicula acrosphaeria, Rabh., 

 var. sandvicensis, Schmidt. 



Epithemia clavata: A. frontal. 

 B. lateral view; 0. small frustule 

 in outline ; all greatly magnified. 



Navicula gibberula, Sm. 



N. gastrum, Ehb. 



N. elliptica, Ktz. 



N. rhouiboides-, Ehb. 



N. gracillima, Pritch. 



Stauroneis phoenicenteron, Ehb. 



Diadesmis confervacea, Ktz. 



Gompbonema dichotomum, Ktz. 



G. intricatum, Ktz. 



G. naviculoides, Sm. 



G. turris, Ehb. 



