COSUARIUM. 



Geogr. Distribution. --Germany. Austria (form) and 

 Silesia. Switzerland. Sweden. Bornliolm. X. 

 Russia. Bosnia. Faeroes. Siberia. Xew Zealand. 

 Brazil. Patagonia (form). 



The var. subpunctulatum differs from the type only in its 

 more prominent and clearly differentiated central granules, 

 which are sometimes disposed upon a very slight median 

 inflation. The character of the apex is very variable, and all 

 states exist from a smooth truncate apex to one which is 

 granulate and slightly convex. It would appear that the 

 zygospore is also somewhat different, that of the var. sub- 

 punctulatum being furnished with a circlet of teeth around 

 the base of each spine (vide PL LXXXIV, fig. 20). This type 

 of zygospore has also been described by Xordstedt for a 

 Brazilian form C. punctulatum subsp. brasiliense Nordst. 

 (vide Wittr. & Nordst. <Alg. Exsic.' 1882, no. 471; fasc. 21, 

 1889, p. 41) which differs from typical C. punctulatum in. 

 the possession of two pyrenoids in each semicell. 



C. punctulatum var. ornatum Istvanffi (' Diag*. praev. Alg. 

 nov. Hungaiv 1887, p. 237) is most probably only a small 

 form of C. punctulatum var. subpunctulatum. 



C. sub punctulatum var. regulars Liitkem. (' Desm. Central 

 China,' 1900, p. 120, t. 6, f. 16) should, on the other hand, be 

 referred to C. subtriordinatum W. & G-. S. West (' AVelw. 

 Afric. Freshw. Alg/ 1897, p. 122, t. 368, f. 11), a tropical 

 species not very far removed from the C. punctulatum 

 species-group. 



Var. rotundatum Klebs. (PI. LXXXV, fig. 12.) 



C. punctulatum var. rotundatum Klebs, Desm. Ostpreuss. 1879, p. 37, 

 t, 3, f. 52, 54, 56 (= /5), not f. 60 (= a); West, Alg. X. Wales, 1890, 

 p. 289. 



? ? C. punctulatum var. Klebsianum Turn. Freshw. Alg. E. India, 1893 

 p. 5-i, t. 7, f. 36 [= C. Klebsianum Turn. 1. c. p. 55 (note)]. 



Semicells somewhat inflated, not so pyramidate, 

 apex convex ; granulation even, without any differen- 

 tiation. 



Length 3 7 JJL; breadth 29 /z,; breadth of isthmus 10/x,. 



WALES. Snowdon, Carnarvonshire ! 



G-eogr. Distribution. India. 



It seems probable that the form we have figured (PI. 

 LXXXY, fig. 12) is to be referred to two (if not more) of the 



