128 



OOCYSTIS AND EREMOSPHiERA, 



British Frw. Alg?e is narrowly elliptic, with acutely rounded 

 ends, the membrane at the poles being incrassate on the inner 

 side only. The chloroplasts are discoid. From all accounts, the 

 ratio of length to breadth varies from 1"5 to 2*1 : 1*0, with which 

 our specimens agree; 1 "74: 1*00 average of 9. 



Text-fig. 17.— («) O. -so/lfarki Wittrock,( x 48.5); after G. S. West. (h) 

 Forma major Wille,( x520); after W. West. {<:) Var. maxima Go- 

 mont, ( X 30()) ; ((/) apex ( x 580); after (ionioiit. {e)Vsii: notabileW. 

 West,( X 520), after West. 



Forma ma.tor Wille. (Text-fig. 176). 



Ferskvandsalg. fra Novaja Semblia, 1('^79, p.26. A larger 

 form, the same shape as the type. Wille gives 40 x 22/x as the 

 dimensions, and exactly the same size is recorded by W. & G. S. 

 West, Welwitsch's Afr. Alg., p. 238, for African specimens. I 

 have not noted this form yet. 



Var. MAXIMA Gomont. (Text-fig. 17c, rf). 



"Celluhe ambitu elliptica?, solitariaj, vel 2-4 in familias con- 

 sociata^, 50 ad 6 5 /a longfe, 26 ad 40/x crassse, membrana tenui, ad 

 polos incrassata." Gomont, I.e. 



Flore algolog, de la Haute- Auvergne, Bull, de la 8oc. botan. de 

 France, tom.43, 1896, p..386, PI. x., f. 13. From the text-figure, 

 it will be seen that this form is the same shape as the type in 

 Brit. Frw. Alga?. Borge, Siissw. Ohlor. v. Feuerland u. Isla 

 Uesolacion, p. 23, records ven: maxima at long. 47-51, lat. 26-29/*. 



