76 THE ROYAL SOCIETY OF CANADA 
causing the discolouration was practically monotonic; in all other cases 
I found it very varied as will be seen. My friend, Dr. McLean 
Fraser, informs me, however, that on two occasions he has observed 
the water of Departure Bay discoloured over large areas by a plankton 
which consisted almost entirely of a single species, in the one case 
an undetermined Dinoflagellate, and in the other a species of Noctiluca. 
With the latter form there was some admixture of diatoms, copepods, 
nauplii, etc., but the flagellate was estimated to form at least 95% 
of the entire material. 
2. On September 11th a patch of “brown water’’ of some extent 
was encountered off the entrance to Esperanza Inlet, on the “West 
coast of Vancouver I., and a collection made from it revealed a re- 
markable and interesting variety of forms. 
The only Diatom observed was Coscinodiscus, which was not, 
however, present in any considerable numbers and is identified with 
some hesitation with C. nobilis, Grun. Of the Dinoflagellata, Ceratium 
fusus was quite common, while C. furca and C. tripos, though present, 
were very rare. 
With the exception of these forms the plankton was entirely 
composed of animal forms. No Protozoa were observed, but of 
Coelentera, several forms were present. In the first place a few 
hyrdrothecae were obtained, in all cases quite empty but belonging 
apparently to at least two species of Campannularian hydroids. One 
of them I was not able to identify; the other, represented by hydro- 
thecae whose length and breadth were about equal, which lacked any 
indications of dentations at the margin and were covered more or less 
abundantly with villosities, probably due to wear and tear, my friend, 
Dr. C. McLean Fraser, kindly informs me was probably Obelia longis- 
sima. 
_ An Anthomedusan belonging to the genus Rathkea was present 
in considerable numbers. It is apparently R. blumenbachii (Rathke), 
a form originally described from the Black Sea, but held to be identical 
with R. octopunctata of the north Atlantic. It has recently been de- 
scribed by Bigelow,! 1913, from Behring Sea and probably has a 
circumpolar distribution. 
This last remark is also applicable to the Siphonophore Diphyes 
appendiculata Eschscholtz, originally described? from the north 
Pacific, but also forming an important constituent of the plankton of 
the Mediterranean, Diphyes tripartita Costa being regarded as identical 



1H. B. Bigelow—Proc. U. S. Nat. Mus. XLIV, 1913. 
? Eschscholtz, System der Acalephen. Berlin, 1829. 
