458 
BULLETIN OF THE BUREAU OF FISHERIES 
NOTES ON OTHER UNICELLULAR PLANTS AND ANIMALS 
The flagellates Phaeocystis and Halosphaera and the tintinnid infusorians and 
acantharian radiolarians are secondary in importance to the peridinians and diatoms 
in the plankton of the Gulf of Maine, but are still sufficiently abundant there at 
times to call for brief notice. The last two are grouped here with the phytoplankton 
for convenience sake, though they are animals and consequently consumers and 
not producers. 
PH/EOCYSTIS 
The brown unicellular alga Phaeocystis is the only organism that we have ever 
found rivaling the vernal flowerings of diatoms in the Gulf of Maine either in abun- 
dance of floating vegetable matter produced or in actual numbers. Its identity is 
established by the simple structure of its cells, together with their green color and 
association into slimy colonies. But whether we have to do with Ph. pouchetii, Ph. 
globosa, or with both these species, has not been determined, the precise character 
by which the two are separable — i. e., the form of the colonies, whether lobate 
( pouchetii ) or globose as in globosa (Lemmermann, 1908) — having been destroyed 
either by preservation or by the churning which they underwent in the nets. This 
is unfortunate, because pouchetii, with a range hardly extending south of 55° N. 
latitude in European waters, is decidedly a more northern form than globosa, which 
occurs in maximum abundance in the southern part of the North Sea and in the 
English Channel (Ostenfeld, 1910). 
The Gulf of Maine records for Phaeocystis have been confined to April 18 to 
20, 1920, when it was sparsely represented in the western basin (station 20115) but 
so plentiful off Cape Cod and in the southern part of Massachusetts Bay (stations 
20116 to 20118) that the fine-meshed silk nets used on the surface were clogged 
with its slimy masses after a few minutes towing, making it impossible to obtain a 
representative catch of diatoms or of other members of the phytoplankton. The 
Phaeocystis colored the water brown; in fact, the appearance of the nets as they 
are lifted dripping with brown slime of offensive odor betrays the presence of this 
alga at once. 
Plentiful though Phaeocystis was at this time, its flowering period must have 
been brief, because it was not found in the region in question three weeks earlier 
(stations 20087 to 20090) or off Massachusetts Bay and Cape Cod two weeks later 
(stations 20120 to 20125), and it was not found anywhere in the gulf during the first 
weeks of May, 1915. 
These few records show that Phaeocystis fills much the same biologic niche in 
American as in north European waters. The region of its occurrence in the gulf is 
reconcilable, without discussion, with the neritic habit with which Gran (1902 and 
1912) and Ostenfeld (1910) have credited it, and which its European distribution as a 
whole demands, though it is not confined to the immediate neighborhood of the coast 
in either side of the North Atlantic. It seems a regular event for Phaeocystis to 
appear suddenly in tremendous quantities, and while its maximum flowering falls 
later in the northern than in the southern part of its range, it is characteristic of it to 
dominate the plankton for only a short time at any given region. Off the Norwegian 
