t5onjugat£e, Desmidiacesc, Staurastrum. Il93 



liah. in stagnis in Hibernia, Anglia, Scotia (CiiowE, Cooke), 

 Vogesis (Lemaire), Gerraania (Reinscii), Italia (Noiidstedt), Tyro- 

 lia (Nordstedt), Groeulandia (Nordstedt), Norvegia (Nordstedt), 

 Fenuia ( Kleving), Lulea Lappra. (Boldt), Suecia (Lundell), Arae- 

 rica boreali (Wolle), — Dimens. 37-46*18-30. 



150. Staurastrum alternans Breb. in Ralfs Brit. Desra. p. 132, t. $dl, 2578 

 f. 7, Liste p. 144, Archer in Pritcli. Inf. p. 741, t. II, f. 16-17, 

 Deip. Specim. Desm. subalp. p. 143, t. XI, f. 39-47, Wolle Desm. 



U. S. p. 128, t. 41, f. 26-28, Cooke Brit. Desm. p. 162, t. 54, f. 7, 

 Slaurash^um Iricorne Ralfs in Ann. Nat. Hist. XV, 1845, p. 141, 

 t. XI, f. 2 nec Menegli., Goniocystis {Trigonocystis) hexaceros 

 Hass. Brit. Freshw. Alg. p. 352?, Staurasl.rum dispar Br6b. 

 Liste p. 144, n. 50, t. I, f. 27?, Rabenh. Alg. n. 1593? Desmaz. 

 Cr. de Fr. ed. nova n. 513?, Sfaurasirum dilatatum var. alter- 

 nans Rabenh. Fl. Eur. Alg. III, p. 207. — Semicellulis rugosis, 

 anguste oblougis et e fronte visis inaequalibus (contortis), e vertice 

 visis triradiatis, radiis obtusis, cum illis semicelluIcB inferioris 

 alternantibus; zygotis orbicularis, spinis apice furcatis instructis. 



Hal). in stagnis in Italia (Delponte), Gallia (Brebisson), Bel- 

 gio (De-Wildeman), Britannia (Ralfs, Hassall, Cooke), Germa- 

 nia (IIabenhorst), Austria (Grunow), Suecia (Cleve, Wittrock), 

 Norvegia (Nordstedt), Dania (Jacobsen), Groenlandia australi 

 (Boldt), Nova Semlia (Wille), Americae boreali (Wood, Wolle), 

 Nova Zelandia (Maskell). — Dimens. 21-39 «21-39. — Var. pul- 

 chrum Wille Ferskvandsalger fra Novaja Semlja p. 53, t. XIII, 

 f. 80: fere tam longum quam latum, sinu subrectangulo ampliato 

 constrictum; seraicellulis e basi angusta sursum valde dilatatis, 

 subcuneiformibus, dorso truncato vel late rotundato, angulis plus 

 minus rotundato-obtusis; a vertice visis trigoniis, angulis rotunda- 

 tis, iateribus retusis ; membrana granulata, margine granulato-den- 

 tata. Ad «Norra Gaskap, Kostin Shar)) NovaB Semlia) (Wille), in 

 Norvegia, Sibiria et Groenlandia (Boldt). — Dimens. 32 s 30, latit. 

 isthmi 10 u., 



151. Staurastrum dilatatum Ehrenb. Inf. p. 143, t. X, f. XIII, Micro- sbto 

 geol. t. 34, XII B, f. 17, Ralfs Brit. Desm. p. 133, t. XXI, f. 8, 

 Rabenh. Krypt. Flor. v. Sachs. pag. 189, Alg. sub n. 1208, 1338, 



I^. Eur. Algar. III, p. 207, Desmaz. Cr. de Fr. ed. I, n. 1657, ed. 

 II, p. 1357, Wolle Desm. U. S. pag. 128, t. 52, f. 32-33, Cooke 

 Brit. Desm. p. 162, t. 54, f. 8, Ilansg. Prodr. p. 212, Sfaurastrum 

 dilatatum var. obtusilobum De-Not. Elem. p. 53, t. 4, f. 47 (ra- 



