Conjugatfp, DesmidiacGfe, Xantbidium. 9ld 



sub n. 1446 et 1447, Hedwigia II, p. 63, t. XII, f. 2, t. XIX, f. 4, 

 De-Not. Eleraent. p. 48, n. 35, t. IV, f. 36, Rabenh. Fl. Eur. Al- 

 gar. III, p. 223, Delp. Desm. Subalp. p. 168, t. 13, f. 20-26 p. p., 

 Wolle Desm. U. S. p. 93, t. 22, f. 4-5 (incl. var. hexagonum), 

 Kirchn. Alg. Schles. p. 155, Cooke Rrit. Desm. p. 131, t. 46, f. 1, 

 Hansg. Prodr. p. 192, n. 375, Etiasirum fasciculalnm Kuetz. 

 Phyc. germ. p. 137, Xantfiidium 'polygonum Hassall Brit. Freshw. 

 Alg. p. 300, t. 89, f. i?, Xanthidium fasciculaium var. polygo- 

 num Rabenh. Fl. Eur. Algar. HI, p. 223, Alg. n. 1407, 1854. — 

 Parvum, singulum, sine aculeis 60-77^:55-65, constrictione pro- 

 funde lineari ; semicellulis oblongo-reniforraibus vel hexagoniis, dia- 

 metro duplo longioribus, ambitu aculeis gracilibus geminatis 4-6, 

 a dorso ellipticis, utroque polo aculeis quatuor instructis; promi- 

 nentia centrali brevi,conica, subinde truncata; zygotis orbicularibus, 

 magnis, spinis longis, attenuatis, bifidis obsitis. 



Hah. in stagnis in Italia (De-Notaris, Delponte), Gallia (Bre- 

 BISSON, Petit), Britannia (Hassall, Ralps, Cooke), Germania (Ra- 

 benhorst, Kirchner, Kuetzing), Hungaria (Istvanfpi), Bohemia 

 (Hansgirg, Corda), Suecia (Cleve, Lundell), Norvegia (Nord- 

 stedt), Dania (Jacobsen), Rossia (Artari), Fennia (Elfving), Bel- 

 gio (De-Wildeman), America boreali (Wood, Wolle), Sibiria 

 (Boldt), Japonia (RoY, Bisset), in insula Cuba (Lagerheim). — 

 Var. minus Wolle Desm. U. S. p. 93, t. 22, f. 6-7, Hansg. I. c: 

 minus, aculeis brevioribus. In stagnis Americae borealis, Boliemise 

 etc. — Var. ornatum Nordst. Desmidieer fr. Gronland p. 12, t. VII, 

 10: forma tumore centrali granulato (in angulis inferioribus tu- 

 more nullo); membrana punctata. Ad a Pakitsok, Sarpiursak )) Gro- 

 enlandise (S. Berggren). — Var. perornatum Nordst. Freshw. Alg. 

 of N. Zeal. and Austral. p. 43, Botaniska Notiser 1887 p. 158, 

 Notarisia 1888, p. 412: semicellulis tumore centrali verrucoso, ver- 

 rucis in centro singulis vel binis, marginalibus concentrice vel el- 

 liptice ordinatis, inter isthmum et tumorem verruca prasditis. Ad 

 « Omatangi » in Nova Zelandia (S. Berggren). — A var. ornaio 

 Nordst. Desm. Gronl. p. 12, tab. VII, fig. 10, angulis inferioribus 

 semicellularura dente granuliformi singulo armatis (ut in a, Ralfs 

 Brit. Desm. tab. 19, fig. 4 b) et verruca ad isthraum pr^cipue dif- 

 fert. Long. sin. acul. 57 u.., lat. 54 a., crass. 32-38 a. — Forma 

 supernumerarium Nordst. 1. c. t. IV, f. 23: semicellulis spina sin- 

 gula supra tumorem centralem paullo infra marginem apicalem 

 posita ornatis, a vertice visis medio utrinque spina infra tumorem 



