86 Myxophycese, Chroococcacese, Microcystis. 



in solidas familias spha^ricas, demum incavatas lobatasque conso- 

 ciatffi, achroo et gelatinoso tegumento circumdatse. Contentus vi- 

 ridi-terugineus, sa>pe vacuola substantiam aeriformem continentia 

 pncbens; famili;e singul;e vel racemose consociata;; divisio cellu- 

 lularum in tres directiones fit. 



1. Microcystis Donnellii Wolle in Bull. Torr. Bot. Club 1879, VI, 219 

 n. 49, p. 282. — Strato sordide luteolo, olivascente; familiis glo- 

 bosis vel ovalibus, 30-70 [i. latis, saipe plus minus angulosis, so- 

 lidis, viridibus, spha^ricis; contentu granuloso viridi; cellulis 2,2- 



4 [j.. crassis. 



Hah. in stagnis, libere natans, loco « Garrett Co. » dicto in 

 ditione Marylandica, Americffi borealis (J. Donnell, Smith). 



2. Microcystis incerta Lemm. in Plon. Ber. XI, p. 300, Polycystis ^20 

 incerta Lemm. Phytoplanct. Sachs. Teiche in Forschungsb. v. 

 Plun. VII, 1899, p. 37. — Strato subsphanico, cellulis pallide neru- 

 gineo-viridibus, subsphsericis, vacuolis gasosis carentibus. 



Hah. « Grossteich » prope « Baselitz » Saxonia^ (Lemmermann) 

 turfosis prope Plun Holsatite (Lemmermann), in lacubus Suecicis 

 (Lemmermann), Danicis (Ostenpeld), Hibernicis et Scoticis (West). 

 — Var. elegans Lemm. in Plon. Ber. X, p. 150 et XI, p. 300. 

 Cellulis subsphtericis 2-2,5 [x. diam. Ia3te cerugineo-viridibus, e 

 multis in strato subsphgerico vel elongato consociatis. In lacul)us 

 « Uklei » et « Ausgraben » Holsatice (Lemmermann). 



3. Microcystis ochracea (Brand) nob., Polycystis ochracea Brand 221 

 Zur Algenfl. der Wiirmsees (1898), p. 200. — Strato submerso, 

 dilute a^ruginoso viridi, siccitate olivaceo-viridi, vel flores aqufe 

 ochraceos vel sulphureos lucidos efficienti; familiis subrotundis 



vel cylindricis vel ellipsoideis vel etiam annulatis vel iniequaliter 

 elongato-cylindratis varieve curvatis et soepius parce ramificatis 

 tegumento mucoso honiogeneo 20-40 [x. et ultra crasso, vix con- 

 spicuo obductis, 50-200 [j.. diam. usque ad 3 mm. long. ; cellulis 

 globosis, divisione incumbente ellipsoideis, singulis vel geminatis, 

 dilutissime viridibus, granulis nitentibus inspersis; in floribus 

 aquse ochraceis, contentu granulari 4,5-6,5 raro usque ad 8 [x. diam. 

 Hdb. in lacu «Wurmsee» BavariGe (Brand) et in lacu « Varano» 

 Italiif (Zacharias). 



4. Microcystis Flos-aquae (Wittr.j Kirchn. in E. und P. Nat. Pfl. p. 50, 222 

 f. 49 N, Potycystis fios-aqum Wittr. in Wittr. et Nordst. exs. 



n. 298! et599 (flde Hansgirg) Hansg. Prodr. II, p. 144. — Strato 



