182 THE CLASSIFICATION OF THE TILOPTEEIDACE^. 



or rarely intercalary sporangia. Sexual reproduction ooga- 

 mous (?), oogonia spherical, slightly flattened below, partly 

 immersed in the frond. Antheridia intercalary, tubular, 

 formed by the transformation of one or more cells in the 

 continuity of the filament. Spermatozoid mother-cells ar- 

 ranged in longitudinal and transverse rows, forming the 

 wall of the antheridial tube. Spermatozoids, bi-ciliated, 

 with two chromatophores. Individuals either asexual, her- 

 maphrodite, or sporo-hermaphrodite. 



Haplospora globosa (Kjellman) limit, mutat. Filaments 

 from an inch to twelve inches long, rich brown, turn- 

 ing olive green on drying, tufted, densely decompoundly 

 branched, branches and branchlets opposite, alternate, sub- 

 secund or scattered. Attachment by means of rhizoids. 

 Cells of the main filaments 60-80ya wide, as long as or 

 slightly longer than broad, those of the ultimate branchlets 

 about 30/x, and much broader than long in the lower part, 

 gradually passing into long narrow cells, which are almost 

 colourless. Chromatophores small, oval, numerous. Asex- 

 ual sporangia globose, 60-100/a (85-114/x. Kjellm.) in dia- 

 meter (usually 60-70ja in Brit, specimens), usually borne on 

 one or many-celled stalks, more rarely sessile or inter- 

 calary. Oogonia spherical, slightly flattened at the base, 

 partly immersed in the frond, 50-80/x (90-118/x. Kjellm.) in 

 diameter. Antheridia 30-150/x, long, 28-50/x, wide. Distri- 

 bution, Scandinavia, Baltic, N. America, Clyde, N.B. 



The question now to be considered is, how does this affect 

 the classification of the Tilopteridacese ? It seems to justify 

 the exclusion from the group of all plants devoid of the 

 characteristic tubular antheridia, the possession of which 

 is perhaps the most characteristic feature now that H. 

 globosa and Sc. speciosa are known to be one species. 

 Scapliospora arctica Kjellm. was considered by E,einke to 



