1911] Kofoid: The Genus Gonyaulax. 245 



(unless it be as Gonyaulax sp.) from Danish waters where Auri- 

 viUus (1898), Cleve (1900b) and also Paulsen (1907) report it. 

 Jorgensen (1899, 1905) reports it rare in Norwegian fiords and 

 Ostenfeld (1899, 1900, 1903) from the neritic plankton at the 

 Faeroes, in adjacent waters north of Scotland (60° N, and 

 4°-6°W) and in the North Atlantic at about 60° N, 31° W. 

 Later Ostenfeld and Paulsen (1904) report other occurrences 

 along the route of Danish steamers going to Greenland in the 

 North Atlantic along the parallel of 60° N at 1°, 13° and 27° W, 

 and in all cases as rare. Stein (1883), Biitschli (1885) and others 

 have found it at Kiel, Schroder (1900) at Naples, Entz (1902) 

 in the Adriatic at Quarnero, and Pavillard (1905) in the Gulf 

 of Lyons, Whitelegge (1891) reports it at Port Jackson, Aus- 

 tralia, during an outbreak of discolored water which he attrib- 

 utes mainly to Glenodinium rubrum, a new species which he 

 describes from the red water. This form looks suspiciously like 

 the contents of Gonyaidax polyedra after ecdysis. Okamura's 

 (1907) record of this species from Japanese waters is to be 

 rejected, since his figure is plainly that of Goniodoma acumin- 

 atum. Karsten (1906) reports it once in the Valdivia Collec- 

 tions from Station 55, 2° 36' N, 3° 27' E, in the Gulf of Guinea, 

 in a locality which is perhaps within the reach of neritic in- 

 fluences. 



The species exhibits as a whole marked preferences for a 

 neritic distribution, with rare occurrences in territory invaded 

 by oceanic currents which may carry occasional individuals away 

 from neritic regions, as in the case of records in the North 

 Atlantic and Gulf of Guinea. Both in local distribution and 

 relative numbers it is remarkably erratic, varying, in seemingly 

 similar regions where other cosmopolitan dinoflagellates occur 

 with greater regularity and uniformity, from an entire absence 

 of all records of occurrence up to overwhelming numbers, which 

 completely mask the other dinoflagellates, and in fact all the 

 microplankton and even exterminate the bottom fauna. The 

 indications are that Gonyaulax polyedra is a species in a pecul- 

 iarly susceptible physiological condition in which the repro- 

 ductive and growth processes may be more than usually sensitive 

 to stimulus by favorable conditions in the environment. ■ 



