KOFOID AND SWEZY: UNARMORED DINOFLAGELLATA 45 



The species of diuoflagellate which has been found most frequently to be 

 the cause of the manifestation of red water is Gonyaulax polyhedra. During 

 the summer of 1914 an outbreak of "yellow water" occurred which lasted from 

 July 27 to August 6, caused by a small species of Gymnodinium, which is here 

 described as G. favum. This was found to occur in small patches, the greenish 

 yellow color of which was very conspicuous on the crest of the breakers near 

 shore. A sharp line of demarcation separated these patches from the unin- 

 fected waters. Okanuira (1916) found that areas of colored water in Yokohama 

 harbor, Japan, in June, 1910-1911, were due to the presence of C ocModinium 

 catenatum. These were present in such vast quantities that the effect upon 

 the marine life in the waters was marked, many fish dying as a result. 



Somewhat similar to these appearances of colored areas of sea water is the 

 occurrence of Aynphidinium on the beach sands at Port Erin, Isle of ]\Ian, as 

 recorded by Herchnan in a series of papers in 1911-1913. These were found 

 in such vast quantities that the sands were colored a greenish brown. They 

 occurred about or a little above the half -tide mark. These deposits were of a 

 varying size, one of the largest covering a continuous stretch of sand about 

 fifty yards long by five yards in breadth. They were visible for periods ranging 

 from a few days to a month, increasing or decreasing or even changing the 

 location according to the stages of the tide. More than one species of AmpM- 

 dinium was found to be present in these colored areas, the predominant one 

 being yi. herdmani (A. operculatum). 



Under ordinary ciremnstanees no zone of decay is found in the l^each sands, 

 since the adjustments of bacterial, plant, and animal life in this region are 

 such that reciprocal growth and decay preserve the balance of the arenaceous 

 habitat, as they do in the pelagic one, without marked localizations of regions 

 of fermentation and decay. That the diatoms play a part in these interchanges 

 and interrelationships within the arenaceous lia1)itat is well known. The only 

 references, however, to the part that dinoflagellates may take therein are those 

 of Ilerdman, who followed for several years the recurrences of patches of 

 Amphidinium followed by nearly equal numbers of diatoms in the same region. 

 From April 7 to November 2, 1911, Attipliidiuinm appeared thus four tunes. 

 This rhytlmiical occurrence of two diffei'ent forms in the same territory is 

 strongly suggestive of the alternations that may sometimes be observed in 

 plants, one plant alternating with another in recurrent occupation of the same 

 region. 



NiTTRiTiox. — The subject of nutrition in the dinoflagellates is one fraught 

 with many misconceptions and inaccuracies, due to the uui)erfect knowledge of 

 the group. West (1916) in his recent book on the Algae in the series of Cam- 

 bridge Botanical Handbooks places the Dinoflagellata with the Algae, stating 

 that over 90 per cent of them are true v(\getal)le organisms with holophytic 

 nutrition. 



