1160 Conjugata3, Desmidiacei'e, Staurastrum. 



visis 3-radiatis, ssepe ob torsionem ciim illis alterius semicellulne 

 alternantibus. 



Hab. iu stagnis ad «M. Everett, Massach. » America^ borealis. 



— Diam. 20-25 [x. Slaurastro gracili Ralfs subaffine. 



04. Staurastrum tuberculatum Benn. in Journ. Royal Micr. Soc. 1880, ?79i 

 p. 12, t. II, f. 24. — Mediocre; semicellulis subhexagoniis, lateribus 

 superne rectis vel leniter convexis, iaferne concavis; raargine in 

 parte superiori semicell. granulis margaritaceis instructo; membrana 

 tuberculata. 



llah. in aquis stagnantibus a Loughrigg)) Britannia) (A. W. 

 Bennett). — Dim. cell. 70 =; 55. Lat. apic. semicell. 37 a. Lat, isthm. 

 30 [x. Inter S. crisiatum Arch. et S. Scbaldi Reinsch fortasse di- 

 sponendum. 



05. Staurastrum subarcuatum Wolle Desm. U. S. p. 140, t. 40, f. 15-10. 2??^ 



— Staurastro arcuato Nordst. proximutn at minus, aculeis angulo- 

 rum terminalium minus elongatis, granulis marginalibus tantum raro 

 bifidis; e vertico visum granulis papiII?eformibus concentrice dispo- 

 sitis, srepe e margine protrudentibus ornatum. 



Hab. m America boreali (Wolle). 

 00. Staurastrum Boldtii De-Toni, Staurastrum cuneatum Roldt 2794 

 Sibir. Chloroph. p. 114, t. 5, f. 24, nec Wolle. — Parvum, tam 

 longum quam latum vel paullo longius, incisura mediana profunda, 

 rectangulari ; semicellulis late cuneatis, sursum dilatatis, dorso (me- 

 dio subtruncato) leviter convexo, lateribus rectis, membrana mar- 

 gineque granulatis, granulis in series transversas ordinatis, utroqiie 

 fine aculeis binis subtilibus instructis; e vertice visis triangularibus, 

 lateribus retusis, angulis rotundatis, apice aculeis binis arraatis, 

 ffranulis in series transversas ordinatis, medio dorso levi. 



Ilab. ad uFatianoskaja)) Sibiri?e. — Dimens. 21,0-22,8:5 21,0; 

 lat. isthm. 0-7,1 u, 



07. Staurastrum cyathodes Josh. Burmese Desmidiere p. 042, t. XXIII, 27&J 

 f. 22-23. — Mediocre; semicellulis cyathiformibus ; triangularibus 

 brachiis longe productis, profnnde fissis et trifiircatis, medio pro- 

 funde constrictis, puncto junctionis minuto; a vertice conspectis 

 brachiis minute granulatis,granulis secus series tros dispositis; mem- 

 brana haud omnino levi. 



Ilab. in Pistia stratiote ad u Rangoon » in Birmania Asiai 

 (R. RoMANis). — Long. sino spinis 40 u.., longit. ab apicibus 04-74 [j.. 

 Lat. sine brachiis 22 y.,, lat. ab apicibus 47-50 fjt., Isthmi lat. 3 ,u. 



08. Staurastrum Novse-Caesareae Wolle Desm. U. S. p. 145, t. 47, 2796 



