1200 Conjugatas, Desmidiaceas, Staurastsura. 



Rabeiih. Fl. Eur. Algar. III, p. 221, Wolle Desm. U. S. p. 145, 

 t. 41, f. 7, Cooke Brit. Desm. p. 1G4, t. 5G, f. 1, Didumocladon 

 longiapinum Bailey in Sraiths. Contr. of Knowl. 1850, p. 3G, t. 1, 

 f. 17, Slaurasirwn bideniaiam Wittr. Anteckn. 18G9, p. IG, f. 7. 

 — Magnum; semicellulis e fronte visis triangularibus , truncatis, 

 in margine interiori levibus, in unoquoque latere in processus 2 

 valde elongatos, apice subacutos, invicem superpositos abeuntibus, 

 divergentibus; e vertice visis trigoniis, unoquoque apice processu 

 terrainato, lateribus subplanis. 



liab. in stagnis in Hibernia (Arciier), Suecia (Lundell), Nor- 

 vegia (Nordstedt), America boreali (Bailey, Wood, Wolle). — 

 Dimens. 9G-I08 :i 90-102. Ex Wolle diam. cell. 75 [j.., cum spinis 

 150 a. 



171. Staurastrum brasiliense Nordst. Desm. Bras. p. 227, t. 4, f. 39, 2899 ~ 

 Hedwigia 1870, p. 18G, Wolle Desm. U. S. p. I4G, t. 48, f. 1-3. — 

 Magnura, tertia parte circa longius quam latius, profunde constri- 

 ctum, sinu araplo; semicellulis breviter cuneatis, sursum dilatatis, 

 dorso truncatis vel raodice retusis, angulis in 3 aculeos firmos di- 

 vergentes fissis; a vertice visis 4(-5)-angularibus, angulis in acu- 



leos 3-4 (semel invent.) flrmos, longos, divergentes fissis, lateribus 

 concavis; membrana punctata; articuli conjunctivi latitudine circi- 

 ter dimidium diametri transversalis semicellulao sequante. 



Hab. ad «Lagoa Santa» (Warming) et «Caldas» (Regnell), 

 in Brasilia Americae australis; in New Jersey et Alabaraa Ame- 

 ricc'1) borealis (Wolle). — Long. s. acul. 43-51 a., long. c. acul. 

 56-77 [j.., lat. s. acul. 25-37 a., lat. c. acul. 65-99 a. — Var. tri- 

 quetrum Wolle Freshw. Alg. U. S. p. 46, t. 60, f. 39-40: a typo 

 differt cellulis e vertice visis trigoniis magnitudineque minori. In 

 stagnis pr. lacura «Tahoe» circa «S. Francisco» in California 

 Aniericaa borealis (D.""" Hanson et Haggin). — Diam. cell. (incl. acul.) 

 63-67 a. 



172. Staurastrum Cerberus (Bailey) Arclier in Priteh. Inf. p. 739, 2900 

 Wolle Desm. U. S. p. 142, t. 45, f. 7-8, Didijmocladon Cerberus 

 Bailey in Smiths. Contr. 1850, p. 36, t. 1, f. 15-16.— Parvura, tam 

 longum quam latum, sinu rotundato, superficie levi ; seraicellulis 

 oblongis, utroque fine sinuato-truncatis, angulis in aculeura cuspi- 

 (hitura productis, in niedio sursum et deorsura prominentiis geminis, 



in aculeum elongatis instructis, a vertice triangularibus, angulis in 

 apice truncato- vel sinuato-bi-cuspidatis, sub apice aculeis geniinis 

 brevibus praeditis. 



