293 



other genera. Within the Gym no di ni da e occurs the most persistant 

 tyije, in the case of Spirodinium geminatum where the species occurs, 

 as a rule, and perhaps always, in short chains of two or four individuals, 

 each with its complement of furrows, flagella and nucleus. 



In Polykrikos, however, the colonial organization is permanent, and, 

 moreover, the individual organization of the separate zooids is modified 

 to the extent that nuclear division does not always occur coincidently 

 with the multiplication of superficial structures such as furrows, flagella 

 and the inter-zooidal constrictions. Nuclear division thus lags behind, 

 and suspends the completion of the zooid formation until the next fol- 

 lowing division of superficial structures is impending. 



The presence of the normal complement of two flagella for each 

 zooid of Poli/krikos not only demonstrates its close relationship to Gym- 

 nodinium but it also removes the most important distinction on which 

 Polykrikos auricularia Bergh (1881) was founded. It seems probable 

 that this species is in reality identical with P. schivartxi Bütschli and 

 must accordingly be reduced to a synonym. My examination of many 

 individuals shows that the other distinctions upon which Bergh founded 

 his P. auricularia break down as species characters. A full discussion 

 of the organism will be found in a final paper to appear shortly. 



We may therefore conclude that Polykrikos is a colonial organism 

 of 2, 4. or rarely 8 zooids and belongs in the family Gymnodinidae. 

 Its place in the system may be indicated as follows : 



Subclass Dinoflagellata. 

 Family (lymiiodinidae. 

 Sub-family Polydininae. 



Gymnodinidae with colonial organization. Nettling organs pre- 

 sent. Represented by a single genus and species Polykrikos auricularia 

 Bütschli. In neritic plankton on coasts of Europe and California. 



Berkeley, California, Nov. 10, 1906. 



8. Experimente mit Riesenschlangen zur Feststellung ihres Nahrungs- 

 quantums. 



Von Dr. Alexander Sokolowsky. zoologischer Assistent am Tierpark Hagenbeck. 



(Mit 1 Figur. 



eingeg. 29. November 1906. 



Um die Größe der Freßlust der Riesenschlangen zu bestimmen, 

 wurden seit vorigem Winter bis auf den heutigen Tag im Hagenbeck- 

 schen Tierpark in Stellingen wiederholt Experimente ausgeführt, 

 über deren Resultate ich im folgenden kurz berichten will: 



Während früher angenommen wurde, daß die Riesenschlangen nur 



