COSMAIUUM. 201 



49. Cosmarium pseudopyramidatum Lund. 

 (PL LXIV 5 figs. 9-12.) 



Cosmarium pyramidatum Breb. in Ralfs' Brit. Desiii. 1848, p. 94, t. 15, 



f. 4d, e,f. " 

 C. pyramidatum Breb. var. minus Eeinsch in Rabenh. Alg. 1868, no. 1902, 



f. 6. 

 C. pseudopyramidatum Lund. Desm. Suec. 1871, p. 41, t. 2, f. 18; Nordst. 



Desm. Spetsb. 1872, p. 29 ; Wolle, Desm. U.S. 1884, p. 69, t. 15, f . 11-13, 



t, 16, f . 5, 6 ; Cooke, Brit. Desm. 1886, p. 86, t. 37, f . 2 ; Hansg. Prodr. 



Algenfl. Bohm. 1888, p. 198 ; De Toni, Syll. Alg. 1889, p. 946 ; West, 



Alg. N. Wales, 1889, p. 288 ; Heimerl, Desm. alp. 1891, p. 597 ; West, 



Alg. W. Ireland, 1892, p. 144 ; Alg. Eng. Lake Distr. 1892, p. 724 ; 



Eoy & Biss. Scott. Desm. 1894, p. 172; West & Of. S. West, Alg. Madag. 



1895, p. 56 ; Some N. Amer. Desm. 1896, p. 246, t. 15, f . 2 ; Nordst. 



Index Desm. 1896, p. 210 ; West & Cr. S. West, Welw. Afric. Freshw. 



Alg. 1897, p. 115; Alg. S. England, 1897, p. 485 ; Alga-fl. Yorks. 1900, 



p. 78 ; Alg. N. Ireland, 1902, p. 33. 

 Euastrum (Cosmarium) pseudopyramidatum Gay, Monogr. loc. Conj. 1884, 



p. 60. 

 Ursinella pseudopyramidata Kuntze, Revis. gen. plant. 1891, p. 925. 



Cells of moderate size, about If times as long as 

 broad, deeply constricted, sinus narrowly linear ; semi- 

 cells truncate-pyramidate or truncate-semi-elliptical, 

 basal angles rounded, sides convex and converging to 

 apex which is narrowly truncate, upper angles obtuse. 

 Side view of semicell broadly elliptic. Vertical view 

 elliptic, ratio of axes about 1 : 1*8. Cell- wall distinctly 

 punctate. Chloroplasts axile, each with one pyrenoid. 



Zygospore globose or ellipsoid, furnished with 

 scattered submamillate warts. 



Length 43-50 p.; breadth 25-33^; breadth of 

 isthmus 7-10*5 /x ; thickness 17-19'5ju,; diam. zygosp. 

 with warts 32-44 /x. 



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

 W., N., and E. Yorks! Warwick (Wills). Surrey! 

 Hants! (Bennett). Devon! Cornwall! (Marquand). 



WALES. Near Bethesda ! , Capel Curig ! (CooJce 

 Wills), Grlyder Fawr ! , and Pen-y-gwryd (Roy), 

 Carnarvonshire. Llyn Coron, Anglesey ! 



SCOTLAND. Sutherland ! , Ross, Inverness ! , Aber- 

 deen, Kincardine, Forf ar ! , Perth ! , Dumbarton, Argyll, 

 Arran (Roy Bissett). Stirling! Common in the 

 Outer Hebrides ! 



VOL. ir. 14 



