28 



consociatis , in stratum tenue saepius late extensum amoene roseum 

 aggregatis. v. s. 



Diam. cell. l / 30 oo — Vi50o'" = 0,00003 — 0,00006", famil. ad 

 i/ 594 "< = 0,00015". 



Hab. in muris calce illitis cubiculorum humidorum in Italia 

 (Meneghini, L. Kota) ; in Stiria (de Heufler), ad Botzen (de Hausmann), 

 in muris vinearum prope Voslau in Austria infer. (Pokorny). 



P. persicinus (Protococcus persicinus Diesing Mspt. et in litt. 

 Menegh. Nostoch. p. 13. N. 13. T. I. F. 3. a. b. Ktz. 1. c). P. aqua- 

 ticus , cellulis minutissimis , sphaericis rel (post divisionem factam) 

 angulosis, subachrois, pellucidis, aetate provectiori nubilosis, et singulis 

 et geminis , tegumento delicatissimo involutis , in stratum perficinum 

 coadunatis. v. s. 



Diam. cell. 7 2 ooo — 7 1500 '"- 



Hab. in algis majoribus aquarum thermalium in Italia. 



P. roseo-persicinus (Protococcus roseo-persicinus Ktz. 1. c. Suring. 

 obs. phycol. p. 55. N. 2136. Kabenh. Alg. N. 986! Fleischer in 

 Hedwigia II. p. 37. Aresch. Alg. Scand. N. 242 !). P. aquaticus, 

 ceilulis inaequalibus nubilosis, et singulis et geminis, tegumento hyalino 

 velatis, in stratum tenue submucosum roseo-persicinum coacervatis. v. v. 



Diam. cell. Vi400 — 7593"' = 0,000063 — 0,00015". 



Hab. in stagnis plantas aquaticas submersas saepe dense investiens, 

 nec raro in aquae superficie natans, per totam Europam. 



Huc spectant teste D. Brebissonio species sequentes mihi non 

 satis cognitae. 



P. rufescens Breb. (in litt. Protococcus rufescens Ktz. Tabul. I. 

 p. 9. N. 68.). P. cellulis globosis, et singulis et 2 — 4 in familias con- 

 sociatis, in stratum mucosum pallide fuscescens congregatis ; cytiodermate 

 subcrasso , mucoso , achroo , hyalino , lamelloso ; plasmate granuloso, 

 pallide fuscescente. Ad ,,Arromanches u (Lenormand). 



P. coerulescens Breb. (in litt. ad me, Cylindrocystis coerulescens 

 Breb. in Menegh. Nostoch. p. 91.). P. cellulis oblongis , diametro ses- 

 quilongioribus, singulis, saepe geminis ; cytiodermate subcrasso, achroo, 

 diaphano ; plasmate viridi-coerulescente subopaco. 



Ad saxa humida prope ,,Falaise" (De Brebisson). 



P. bituminosus (Bory) Trevis. (Algh. corcot. p. 32. N. 39. Chaos 

 bituminosus Bory Dict. cl. III. p. 15. Ann. des Sc. Phys. I. p. 270. 

 Palmella bituminosa Menegh. Nostoch. p. 56. Protococcus bituminosus 

 Ktz. Tabul. I. T. 5. Gloeocapsa bituminosa Ktz. Spec. p. 224. N. 49.). 

 P. thallo mucoso, brunneo-nigro, bituminoso ; cellulis minimis, (\iooo'" 



