COSMARIUM. 241 



p. 60 ; West, Alg. W. It-eland, 1392, p. 155 ; Norclst. Index Desm. 1896, 

 p. 125 ; West & G-. S. West, Ala;. S. England, 1897, p. 490 ; G-. S. West, 

 Alga-fl. Cambr. 1899, p. 218 ; West & GK S. West, Alga-fl. Yorks. 1900, 

 p. 78 ; Borg. Fresliw. Alg. Faeroes, 1901, p. 226 ; West & G. S. West, 

 Alg. X. Ireland, 1902, p. 39 ; Scott. Freshw. Plankton, I. 1903, p. 527 ; 

 G-. S. West, W. Indian Fresliw. Algae, 1904, p. 285 ; West & G. S. West, 

 Freshw. Alg. Orkneys and Shetlands, 1905, p. 21 ; Further Contrib. 

 Freshw. Plankton Scott. Lochs, 1905, p. 484 ; Borge, Beitrage Alg. 

 Schweden, 1906, p. 41. 



C. gradatum Roy, Desm. Alford District, 1890, p. 203 ; Roy & Biss. Scott. 

 Desm. 1894, p. 102. 



Ursinella formosula Kmitze, Revis. gen. plant. 1891, p. 924. 



Cells rather under medium size 1J-- IT times as lono* 



c? J O 



as broad, very deeply constricted, sinus narrowly linear 

 with a slightly dilated extremity; semicells trapezi- 

 form-subsemicircular, basal ano-les rounded, sides 



7 o ' 



convex and 6-7-crenate, with the 3 superior crenations 

 bigranulate, lower ones entire, apical angles scarcely 

 obtuse or faintly bigranulate-emarginate, apex truncate 

 and 4 (rarely 6-7)-crenulate, within the margin very 

 minutely granulate, granules in concentric and radiating 

 series, binate except in the innermost series and near 

 the basal angles, in the centre with a broad tumour 

 furnished with 5-7 vertical series of granules. Side 

 view of semicell broadly ovate, strongly granulate on 



t/ O / <^ 



the tumid margins near the base on each side. Vertical 

 view rather narrowly elliptic, poles rounded and 



minutely crenulate, with a broad 5 7-crenulate tumour 



i/ ^ 



at the middle on each side, in the centre with a rather 

 small rectangular smooth area. Chloroplasts axile, 

 with two pyrenoids. 



Zygospore unknown. 



Length 40-50 \L\ breadth 34-40 p, ; breadth of 

 apex 12-1 7 p.; breadth of isthmus 10-15'o JJL ; thick- 

 ness 22-25 p.. 



EXGLAXD. Cumberland ! Westmoreland ! TT., X., 

 and E. Yorks ! Cambridgeshire ! Middlesex ! Surrey ! 

 Kent! Hants ! (Rot/). Cornwall! 



WALES. Grlyder Fawr (Rot/), and near Bettws-y- 

 Coedl, Carnarvonshire. 



SCOTLAND.- -Caithness, Eoss, Inverness !, Aberdeen !, 

 Kincardine, Forfar, Fife, Wigtown (Roij 4* Bissett). 



VOL. III. 16 



