Conjugatae, Desmidiaceae, Cosmarium. 979 



B. Membrana verrucosa, rarius tantum grosse punctata. 



114. Cosmarium margaritiferum (Turp.) Menegh. Synops. in Linn. 2351 

 1840, p. 219, Ralfs Brit. Desmid. p. 100, t. XVI, f. 2, Breb. Li- 

 ste p. 128, Thomas in Transact. Micr. Journ. III, 1855, p. 33, t. 

 V, f. 1-33, Rabenh. Alg. n. 626, Fl. Eur. Algar. III, p. 157 ex 

 parte, Griffith et Henfr. Micr. t. X, f. 21, De-Not. Eleraent. p. 44, 

 t. IV, f. 29, Delp. Spec. Desm. subalp. p. 123, t. 9, f. 5-9, Wolle 

 Desm. U. S. p. 74, t. 13, f. 1-3, Kirchn. Alg. Schles. p. 150, 

 Cooke Brit. Desm. p. 102, t. 39, f. 2, Hansg. Prodr. p. 198, n. 

 403, De-Toni e Levi FL Alg. Ven. III, p. 49, Micrasterias mar- 

 gariiifera Breb. Alg. Fal. p. 55, t. 7, Cymbella reniformis Ag. 

 Consp. Diat. p. 10, Heterocarpella Ursinella Kuetz. in Linnaea 

 1833, p. 598, Euasirum margaritiferum Ehrenb. Abh. 1833, p. 

 246. Inf. p. 163, t. XII, f. VII ex p., Bailey in Amer. Journ. p. 295, 

 n. 8, Ursinella margaritifera Turp. Dict. Sc. Nat. 1820, f. 23, 

 Mera. du Mus. XVI (1828), p. 316, t. XIII, f. 19. — Subduplo 

 longius quam latius, 26-70 i; 25-60, sinu angusto, extrorsum sub- 

 ampliato, isthmo 10-22 y.. lato; seraicellulis semicircularibns, re- 

 niformibus vel ovatis, basi reniformi, angulis inferioribus late ro- 

 tundatis, lateribus brevibus convexis, apice late rotundato, non 

 explanato; chlorophoris in utraque semicellula binis; cellulis e 

 vertice visis ovatis ; membrana jequaliter verrucis margaritaceis, 

 rotundatis obsita; zygotis orbicularibus, aculeis furcatis vel furcato- 

 ramosis, basi incrassatis ornatis. 



Hab. in aquis limpidis, praesertira turfosis, fontibus, nec non 

 in rauco puteorura parietes obducente, in Italia (De-Notaris, Del- 

 PONTE, De-Toni, Levi), Belgio (De-Wildeman), Gallia (Brebisson, 

 Petit, Gay), Vogesis (Lemaire), Britannia (Archer, Ralfs, Cooke), 

 Germania (Rabenhorst, Kirchner), Hungaria (Istvanffi), Bohe- 

 mia (Hansgirg, Schroeter), Austria (Grunow), Suecia (Cleve, 

 Lundell), Norvegia (Nordstedt), Dania (Jacobsen), Rossia (Ar- 

 TARi), Neerlandia (Suringar), Sibiria (Boldt), Groenlandia (Boldt), 

 Fennia (Elfving), Araerica boreali et Mexico (Wood, Wolle, 

 Bailey), Brasilia (Nordstedt). — Var. incisum Kirchn. I. c. p. 15, 

 Hansg. I. c. : semicellulis ovatis, basi explanato-corapressa; sinu 

 extrorsura sequaliter ampliato. Cum specie passim. 



115. Cosmarium Botrytis (Bory) Menegh. in Linnaea 1840, p. 220, Ralfs 2352 

 ]. c. t. XVI, f. 1, Breb. Liste p. 128, Rabenh. Bacill. n. 17, Alg. n. 

 787!, 1588 et 1960, Grun. in Rabenh. Beitr. II, p. 15, t. H, f. 26, 



