1925] Setchell-Gardner: Melanophyceae 443 



Examination of a small piece of authentic material of 8. fascicu- 

 latum Saunders collected at San Pedro, California, in August, 1896, 

 revealed the presence of specimens of the same three species mentioned 

 under 8. corymbiferum, collected by Mrs. Johnston at the same place 

 and in the same month. S. anomalum is undoubtedly the one to which 

 Saunders refers as 8. fasciculatum Thuret. It does not seem, how- 

 ever, to be Thuret's species, if we have a correct conception of what 

 S. fasciculatum Thuret includes. His species was published in Le 

 Jolis, Algues marines de Cherbourg, no. 100, and in Liste, 1863, p. 73. 

 Thuret quotes as a synonym, 8. volubilis Pringsheim (Beitr. Morph. 

 Meeresalg., p. 13, pi. 3, fig. B, read in 1862). Pringsheim 's figure 

 of volubilis shows the gametangia fasciculately branched, and he states 

 that this character is one of the chief characters of the genus Stre- 

 blonema. This figure has been much quoted since. Pringsheim gives 

 no measurements of the parts, neither does Thuret. 



Reinke (Algenfl., 1889, p. 41) recognizes Streblonema as a subgenus 

 of Ectocarpus. He recognizes Pringsheim 's plant, quoting the fore- 

 going figure, but since volubilis was already occupied by Crouan (1867, 

 p. 161) and fasciculatum was occupied by Harvey (Phyc. Brit,, pi. 

 273), he renamed the plant, calling it Pringshcimii. Hauck (1884, 

 p. 323) seems to have been the first to give measurements of the 

 various parts of the plant. He lists it under Streblonema, cites the 

 above literature of Thuret, and quotes S. volubilis Pringsheim. Con- 

 sidering Pringsheim 's plant, recognized by Reinke and Hauck, as 

 being the same as Thuret's, and taking Pringsheim 's figure and 

 Hauck 's measurements as being correct for Thuret's 8. fasciculatum, 

 then our plant is distinct and undescribed. 



There is a little doubt in our minds at present whether the plant 

 we have described as Streblonema anomalum is one or two species. 

 We do not find the filaments bearing the zoosporangia in the type 

 material examined to be like those figured by Saunders. His figures 

 show the main filaments as being like those of all the known Streb- 

 lonemas, monosiphonous, while those in both collections of material 

 which we have examined are uniformly polysiphonous, that is, the 

 cells of the main central parts of the thallus are divided once or twice 

 lengthwise. This never takes place in the plants which bear game- 

 tangia and which are intimately associated with them. 



The measurements, method of branching of the two sets of plants, 

 and their chromatophore characters are practically the same. At 

 least two interpretations of this polysiphonous phenomenon appeal 



