FRESHWATER AT/i.K. 



57 



PLATE III. 



Fins. 123-125. Xiixtu/' ilisi-ifonni' sp. n., young colonies. (12:1, x 14"; 121-125. x 5nn.) 



Fie. 12C,. Xuxliii- ilim ifunii/' sp. n., tliulli. (Natural size.) 



Fins. lL'7-130. N*tr dixi-ifurme sp. n. 127, 12s, two tilamcnts : 127. with spores ; 12'.*. two groups nf 



spores; ]3ii, filament with sheath. (127. 12*. l:',o. x .".mi : 12'.i, x 700.) 

 Fin. 131. NnxtiH- i/ixfi/'iirm/' sp. n., small part of a mature' thallus. (x 80.) 

 Fn;. 132. frog/in- liiiiifx/ir/i sp. n., thalli. (Xatural size.) 

 Fuss. 133-134. Xostiir /iitii/s/ufli sp. n., young colonies, (x 5on.) 



Fiiis. l:>5-l;;i;. filaments with spores. (135, x 7oit ; 130, x .".00.) 



Fio. 137. small part of a mature thallus. ( X 30.) 



Fie. l:>x. Nostoc fuscescens sp. n., thalli. (Natural size.) 

 Fifi. 13!i. a youni; thallus. ( X 400.) 



PlOS. 140-142. ., filaments. (140, 142, X 700 ; 141, X 500.) 



Fins. 143-144. young thalli. (x80(t.) 



Fins. 1 1.'i-Mi;. Tuly [ml ltn.r <-<>n<iliitinnt<t I'.oizi. 14">, a small part of the richly liranched tilainent : 



146, the end of one of the branches, (x - r .iMi.) 

 Fin. 147. h j i-(igilni-i(t i- urtii Van Heurck. (x 1350.) 

 Fins. 14s, 149 and \Wii..}ffloaii-ii sp., rf. \\. 41!. ( X l:'..".ii.) 

 Fii;. l"i(. ? CycloMla o/ifn-itlafa Kiitz. (x ."..".(i.) 

 FK;. l.'.l. Coscinodiscus decipiens GTUT\. (x 1250.) 

 Fins. l;"c' and l~>-2ti. liiiitinna tlti/ii/it/tnii A.%., var. ehri'iibrri/i (Kiitz.) W. Sm. ; 152, girdle-view : 



lif'a, valve- view. (152, x 1950; 152rt, x 135n.) 

 FII;. \~>:\.N(tvii-ula borenlix (Ehrb.) Kiitz. (x 9m>.) 

 Fins. 154, 155. Nurii-iila i/lnliif<-/n< Ore;,'. ; 154, f. ain/ifiii-'-j>liit/a ,- 155, f. dmyata. (151, x IL'.'.O; 



155, X . r )(i.) 



Fins. 150, 157. Denticiila ti'imix Kiitz. var. fin/firr/ira var. nov. (15fi. x 125o ; i:,7. x 15oo.) 

 Fn;s. 15s-li;n. Calotlirii- intn'i-atit sp. n. ; 15.x, :l typical part of the stratum (the irii-limiics are only 



shown in two cases) ; 1511, ICO, single filaments. (158, X H>0 ; 15!>, x sun ; ICO, x ' .) 



Fics. 1C.1-1C3. Ciilnllirij- ,1/itinrtini sp. u. ; 1C1, 1C.-', filaments shnwinj-' false branching. (liH, 1C2. 



X 400 ; 1C3, X 55n.) 

 Fin*, liil-172. Calottvrix gracilis sp. n. Id, filament showinjj false branching; ](!5, 172. typical 



tilaments ; 1UC., 1(17, base of two filaments, showing inflation; 17", part of a filament 



showing an intercalary heterocv>t : 171. base of filament with a subconical lietenn-\>(. 



(Ifil, 1C,:,, x 5iiO; IC.C-KV.l, 171, 172, X 7no ; 17n. X 12oo.) 



