COSMAKll'M. 235 



Banff, Aberdeen !, Kincardine, Forfar, Perth !, Stir- 

 ling (Roy $' Bissett). Orkneys ! Shetlands ! 



IRELAND.- -Donegal ! Gralway ! Kerry ! Armagh ! 

 Down ! Londonderry ! 



Geogr. Distribution. France. Germany. Galicia 

 in Austria. Norway. Denmark. Sweden. Bornholm. 

 Poland. Faeroes. Iceland. Japan. United States. 



C. Boeck-ii is widely distributed in the British Islands, 

 occurring both in bogs and at the weedy margins of ponds 

 and lakes. The peculiar crenatioii of the lateral margins of 

 the semicells is very characteristic, although to a certain 

 extent resembling that of C. quinarium. The central granules 

 are normally four in number and disposed in the form of a 

 cross, but they are subject to considerable variation. One or 

 more of them may be duplicated either in a vertical or longi- 

 tudinal direction. This variation, however, does not obliterate 

 the general disposition, which still remains fairly evident. 

 We have illustrated some of these various dispositions of 

 central granules in figs. 27-32, pi. LXXXYI. 



203. Cosmarium calcareum Wittr. 

 (PI. LXXXVII, figs. 1, 2.) 



Cos/mi i-inm calcareum Wittr. Gotl. Ol. sotv. Alg. 1872, p. 58, t. 4, f. 13 : 

 Cooke, Brit. Desm. 1886, p. 94, t. 37, f . 12 ; Boldt, Desni. Gronland, 

 1888, p. 23 ; De Toni, Syll. Alg. 1889, p. 1047 ; Eoy & Biss. Scott. Desni. 

 1894, p. 44; Nordst. Index Desni. 1896, p. 71 ; Bohlin, Flor. Algol, d'eau 

 donee d. Acores, 1901, p. 65 ; Borge, Siisswasseralgeii Siid-Patagon. 

 1901, p. 26, t.' 1, f . 9 [forma] ; Alg. erst. Eegnell. Exped. II. Desmid. 1903, 

 p. 101 ; West & G. S. West, Freshw. Alg. Orkneys and Shetlands, 1905, 

 p. 20. 



Ursinella calcarea Kuntze, Eevis. gen. plant. 1891, p. 924. 



Cells small, a little longer than broad, very deeply 

 constricted, sinus narrowly linear ; semicells trapezi- 

 form-semicircular, basal angles subrectangular, sides 

 convex, lower half of sides minutely 4-crenulate, upper 

 half with one emarginate crenation, apical angles 

 scarcely obtuse, apex truncate and straight, minutely 

 6-7-crenulate, minutely granulate within the margins, 

 granules disposed in radiating series and extending 

 almost or quite to the central tumour, in the centre 

 with a very small granulate tumour, 8-11 peripheral 

 granules surrounding- 1-4 central ones. Side view of 



o ~ 



semicell ovate, witli 3-4 pronounced marginal granules 



