283 
sporangia occur in the same plant as sexual organs, (e. g. Callithamnion corymbo- 
sum, cf. THURET in LE Joris” Liste d. Alg. mar. de Cherbourg, p. 112). 
As will be seen from the above, there are many features in the Cryptonemi- 
ales which call for further cytological investigation, especially with regard to the 
presence of a fertilisation process and the manner in which nuclear division takes 
place in the tetrasporangia. The latter point will doubtless be the easier to decide, 
as the tetrasporangia are in many species easily found, and contain large nuclei. 
