192 THE BOTANICAL MAGAZINE. [Vol. xxxi. No. 367. 



Rhizoclonium arenosum Kutz. 



Spec. Alg., p. 384. — Wittr. et Nordst. : Alg. Acq. Dulc. Exs., 

 No. 627.— De Toni : Syll. Alg., I, p. 281. 



= Conferva arenosa Carm. : in Harv., Manual, p. 130. — Harv. : 

 Phyc. Brit., PL LIV, fig. C. 



This species has been hitherto known in a comparatively 

 limited area and it is interesting to find it on our coast. 

 Locality. Boshu Prov. (F. Sugiyama). 

 Distribution. Great Britain and Ireland; Northern Norway. 



Chaetomorpha confervicola De. Toni. 



Syll. Alg., I, p. 268. 

 = Conferva confervicola Rupr. : Tange des ocli. Meeres, p. 397. 

 ? = Chaetomorpha cannabina Kjellm. : Beringhafvets AlgfL, p. 55. 



Frond capillaceous, simple, many centimeters long, tortuose 

 and intricated; cells cylindrical, 45-60 p. in diameter, 2-5 times 

 as long as diameter, hardly constricted at septal points ; cell- 

 membrane thick, lamellose, about 5.5 p. in the periclinal side. 

 Basal cell of filament much elongated, ending in a deformed 

 knob. 



This specimen agrees with the type specimen of Conferva 

 confervicola Rupr. than with any other described species. 

 Ruprecht describes the species as to have the apical cell of a 

 filament more or less thicker than the rest. This is, however, 

 not constant even in the type and very seldom the case, if 

 ever, in mine. Ruprecht's specimen has the cell-wall nearly 

 as thick as in mine but the lamellar structure was not evident. 

 It still keeps a bright green colour in the cells while in my 

 specimens the content has turned into brownish green. 



The plant undoubtedly stands close by C. tortuosa Kutz. 

 Harvey remarks that the specimen he has received from 

 Ruprecht under Conferva confervicola is hardly distinct from 

 C. tortuosa K'utz. Setchell mentions Conf. confervicola Rupr. 

 in Algae of Northwestern America, p. 222, under C. tortuosa 



