COSMAEIUM. 249 



IRELAND. Louo-li Beo-, Londonderry ! Dublin and 



O t} 



Wicklow (Archer). Carrantuobill, Kerry! Mourne 

 Mts., Down ! 



f.reogr. Distribution. France. Germany. Austria 

 and Galicia. Bosnia (var.). Italy. Xorway. Sweden. 

 Denmark. Bornbolm. Finland. S. Russia. Faeroes. 

 Xova Zembla. Franz Joseph Land. Spitsbergen . 

 Greenland. Australia (var.). New Zealand. S. Africa. 

 Sandwich Islands (var.). United States. Argentina. 

 Patagonia (var.). 



C. speciosum is principally an upland species, occurring in 

 mountainous districts in boggy springs and on dripping rocks, 

 in which situations it is frequently associated with <\ 

 Holmiense, C. ance-ps, C. notabile, C. galeritum, etc. 



Xordstedt, on examining" Swedish specimens sent to him by 

 Lundell, found the marginal crenations to be bigranulate. 

 This form he also observed from Spitzbergen, but associated 

 with it was another form with entire crenations and an 

 absence of the basal granulations. He thereupon divided the 

 C. speciosiim-forms into "a bi forme' and u /3 simplex" (fide 

 Nordst. ' Desm. Spetsb/ 1872, pp. 30-31). We find a British 

 form, however, with entire crenations and distinct basal 

 granules, thus agreeing exactly with Lunclelr's original descrip- 

 tion and fioTire. This form we therefore regard as the tvpe 



O *J 1 



(consult PL LXXXIX, figs. 1-3; fig. 1 is a copy of LundelPs 

 original figure ; fio-s. 2 and 3 are drawn from Yorkshire 



O O O 



specimens), and consequently we are compelled to consider 

 Xordstedt's " a biforme" and " [3 simplex" as varieties of it. 



One of the features of typical C. speciosum is the absence of 

 a basal tumour, the semicells not beino- inflated in the region 



7 C? t-J 



of the basal granules. 



The zygospore of the typical form is not known, but 

 Raciborski has observed the zygospore of an Australian 

 variety (consult C. speciosum var. difficile Racib. ' Desmidyja 

 Ciastonia,' 1892, p. 375, t. 6, f. 16). This zygospore was 

 broadly ellipsoid, with the poles somewhat irregularly pro- 

 duced, and the wall was ornamented with large scattered 

 scrobiculations. 



Var. biforme Xordst, (PI. LXXXIX, figs. 4, 5.) 



C. speciosum Lund, a biforme Xordst. Desm. Spetsb. 1872, p. 30, t. 6, f. 11 ; 

 Wille, Ferskv. Alg. Xov. Semlj. 1879, p. 41 ; Boldt, Desiu. Gronland, 

 1888, p. 20 ; West, Alg. Eiig-1. Lake Distr. 1892, p. 728 ; Liitkem. Desm. 



