Protococcoidefe, Palmellaceae, Pediastrum. 575 



coeriobiis 16-cellularibus, dispositione cellularuin 4-fl2; cellulis in 

 disci medio cruciatini dispositis; coenobiis lacunam singulara cen- 

 tralem et lacunas 4 sub cellulis periphericis prasbentibus. In Ame- 

 rica boreali (Bailey, Wolle). — Var. Cordanum Hansg. Prodr. 

 p. 110, Monactinus siniplex Corda 1. c. Cfr. supra: ca?nobiis 47- 

 cellularibus, dispositione cellularum 4+1 1+32; cellulis periphericis 

 radiatim dispositis, lanceolatis; lacunis sub cellulis periphericis 11, 

 in media coenobii parte 4. In Bohemia (Corda, Hansgirg). — • Var. 

 echinulatum Wittr. in Wittr, et Nordst. Alg. aq. dulc. exs. n. 235 

 et in Botaniska Notiser 1883, p. 149 in notam ad Pediastrtan 

 simpieo3 n. 521: ccBnobiis continuis vel subcontinuis; cellularum 

 membrana echinulato-granulata. In Suecia (Wittrock). 



Species hujus sectionis incertae. 



3. Pediastrum ovatum (Ehrenb.) A. Br. Alg. unicell. p. 81, Rabenh. ^^70 

 FI. Eur. Algar. III, p. 72, Asterodictijon ooaluni Ehrenb. in Mo- 

 natsb. 1845, p. 73, Monactinus ocatus Kuetz. Spec. p. 194. — 

 Cu^nobio reticulato, ad 88 [x. diam. e cellulis ovatis, stilo longo ter- 

 minatis, granulatis, mediis 3, periphericis 10 constituto. 



Hab. in lacu ad «Beeskow» non procul a Berolino Germaniae 

 (Ehrenberg). 



4. Pediastrum Triangulum (Ehrenb.) Braun Alg. unicell. p. 81, Rabeuh. i37i 

 Fl. Eur. Algar. III, p. 72, Asterodictyon Triangbtla/n Ehrenb. in 

 Monatsb. 1845, p. 73, Monactinus Triangaluin Kaetz. Species 



p. 194. — Coenobio ad 125 y.. diam., cellulis triangulatis, levibiis, 

 centro vacuo, mediis 5, sequentibus 10, periphericis 15-16. 



Hab. in lacu ad ((Beeskow» non procul a Berolino Germania 

 (Ehrenberg). 



Seclio 3. Diactinium A. Br.iun [1855]: cuGnobiim e cellularum strato siraplici 

 forraatura, snepe pertusimi vel clatliratum. Cellnlie periplieric.e emarginatye 

 vel bilobae, lobis pleruraque cornutis, centrales integr.e vel eraarginate, 

 rarius bilobce. 



5. Pedlastrum forcipatum (Corda) A. Br. Alg. unicell. n. 9, Hansg. is'?? 

 Prodr. p. 110, Eaastrum foroipatnm Corda .\Iman. de Carlsb. 

 1839, p. 238, t. II, f. 7, E. impressaoi et E. heptagonum Corda 



1. c. — Coeaobiis orbiculai-ibus , continuis, e collulis 7-lG (raro 

 ultra) formato; cellulis periphericis ci!'c. 24 y.. iatis, profunde inci- 

 sis, bilobis, laciniis arcuatim convergentibus, in cornua acuta sensim 

 acuminatis; cellulis centralibus polygoniis vel antice leviter excisi?. 



