COSMARIUM. 165 



159. Cosmarium Portianum Arch. 



(PI. LXXX, figs. 4-7.) H 



Cosmarium, orbiculatum De Bary, Conj. 1858, p. 41, t. 6, f. 49, 50; Delp. 

 Desm. subalp. 1877, p. 11, t. 7, f. 46-48. [Not C. orbiculatum Ralfs, 1844.] 



Cosmarium Portianum Arch, in Quart. Jonrn. Micr. Sci. viii, 1860, p. 235, 

 t. 11 ; in Pritch. Infus. 1861, p. 733; Rabenh. Flor. Europ. Algar. Ill, 

 1868, p. 160, f. xyl. b, c (p. 108) ; Lund. Desm. Suec, 1871, p. 46 ; 

 Nordst. Desm. Ital. 1876, p. 28 ; Wille, Ferskv. Alg. Nov. Semlj. 1879, 

 p. 34 ; Wolle, Desm. U. S. 1884, p. 77, t. 14, f . 12-13 [14 ?] ; Cooke, 

 Brit. Desm. 1887, p. 103, t. 39. f . 3 ; De Toni, Syll. Alo-. 1889, p. 986; 

 West, Alg. X. Wales, 1890, p. 289 ; Alg. W. Ireland, 1892, p. 152 ; Alg. 

 Engl. Lake Distr. 1892, p. 727 ; Liitkem. Desm. Attersees, 1893, p. 558 ; 

 Roy & Biss. Scott. Desm. 1894, p. 171 ; Schmidle, Alg. Geb. Oberrheins, 

 1894, p. 550, t. 28, f. 8; Borg. Ferskv. Alg. Ostgronl. 1894, p. 12; 

 Nordst, Index Desm. 1896, p. 204 ; West & G. S. West, Alg. S. England, 



1897, p. 488 ; Schmidle, Lappmark Slisswasseralgen, 1898, p. 32 ; West 

 & G-. S. West. Alga-fl. Yorks. 1900, p. 72; Alg. N. Ireland, 1902, p. 38; 

 Borge, Beitrage Alg. Schweden, 1906, p. 31. 



C. pseudomargaritiferum Reinsch, Contrib. Alg. et Fungi, 1875, p. 84, 

 t. 16, f. 12 [ = C. Portianum according to Archer]. 



? C. discretum Benn. Alg. N. Cornwall, 1887, p. 17, t. 4, f. 23 [figure bad]. 



? Dysphinctium discretum De Toni, Syll. Alg. 1889, p. 885. 



Ursinella Portiana Kuiitze, Revis. gen. plant. 1891, p. 925. 



Cosmarium Portianum Arch. var. orthosticlium Schmidle, Alg. Geb. Oberr 

 heins, 1894, p. 549, t. 28, f . 7 ; Chlorophy.-Fl. Torfstiche Virnheim, 

 1894, p. 56, t. 7, f. 11 ; Beitr. alp. Alg. 1895, p. 390; West& G-. S. West, 

 Alg. S. England, 1897, p. 488 ; Schmidle, Lappmark Stisswasseralgen, 



1898, p. 32 ; West & G-. S. West, Alg. N. Ireland, 1902, p. 38. 



Cells rather small, about 1J times as long as broad, 

 deeply constricted, sinus gradually opening from a 

 rounded extremity, isthmus slightly elongated ; semi- 

 cells elliptic and granulate ; granules rounded, dis- 

 posed in about 10 vertical series, and sometimes in 

 oblique series also (rarely more or less irregular), with 



about 20-23 visible at the margin of each semicell. 

 . 



Side view of semicell circular. Vertical view elliptic. 

 Chloroplasts axile, one in each semicell, with a central 

 pyrenoid. 



Zygospore globose, furnished with elongated, ob- 

 tusely-coiiical warts. 



Length 30-40 p. ; breadth 22-30 //, ; breadth of isth- 

 mus 8-13 /A; thickness 16-20 (rarely up to 24) /^; 

 diam. zygosp. without warts 31 /u, with warts 40ft. 



ENGLAND. --Cumberland ! Westmoreland! (Bissett). 

 Lancashire ! TT., X., and E. Yorks ! Cheshire (Roy), 

 Surrey! Devon! Cornwall! (Marquand). 



