MARINE ALG^E OF VANCOUVER ISLAND 
123 
The Pacific coast forms of Rhodomela and Odonthalia are all 
quite variable and there is confusion in the determination by 
various writers. The following key may be useful as explaining 
how they are understood by the writer. 
1. Branching spiral, not distichous. Rhodomela. 2. 
1. Branching distichous. Odonthalia. 3. 
2. Main axes long, virgate; ultimate axes short, densely 
branched. R* Larix. 
2. Little distinction between axes of different orders. 
R. lycopodioides. 
3. Organs of fructification in dense glomerules. 4. 
3. Organs of fructification looser, in racemes. 7. 
4. Rachis and branches all flat. 0. semicostata. 
4. Rachis terete or compressed. 0. floccosa. 5. 
5. Branchlets long, slender, recurved, numerous. 
Forma comosa. 
5. Branchlets less differentiated. 6. 
6. Branching rather loose. Forma typica. 
6. Branching quite loose and coarse. Forma macracantha. 
7. Midrib distinct. 0. kamtschatica. 
7. Midrib wanting or quite indistinct. 8. 
8. Rachis and branches sinuous; organs of fructification 
erect and subdistant. 0. lyallii. 
8. Rachis and branches straight; organs of fructification 
appressed. 0. aleutica. 
Dasyopsis plitmosa (Harv. & Bail.) Falkenberg. Setchell & 
Gardner, 1903, p. 337; P, B.-A., No. 942. Comox, Ucluelet, 
Qualicum, Queen Charlotte sound, Macoun. A very handsome 
plant, limited to the Pacific coast of North America, extending 
south along most of California. 
Geiffithsia schousboei Montague. Tilden, Centuries, 
No. 208, as G. opuntioides , specimen from Washington; Little 
Torquit, Macoun. Probably several species of Griffithsia occur 
on the west coast of North America, but it is very seldom that 
they are found in fruit, and specific determination is doubtful. 
The identity of the present form with the European plant of 
the same name seems, however, pretty well made out. 
