CHAPTER XVI 



POLYKRTKIDAE: POLYKRIKOS 



Family 3. POLYKRIKIDAE fam. nov. 



Diagnosis. — G}iimodinioidae with a permanent colonial organization, 2, 4, 

 or 8 zooicls in chain, each zooid. having a Gymnodinium type of structure ; girdle 

 a descending left spiral of one turn ; sulcus extending from apex to antapex ; 

 ocellus and tentacle lacking; plasma colored Avithout pigment; nematocysts 

 present. Marine, eupelagic and neritic, and from warm temperate waters. One 

 genus. 



POLYKRIKOS Biitschli 



Tt'xt figure P 



Polykrikos Biitschli (1873), pp. 673-676, pi. 26, fig. 22; (1885), pp. 1011, 1012, pi. 55, 



fig. 8. 

 Polijkrikos, Savillc-Kuut (1880-82), pp. 858, 860. 

 Polykrikos, Bergh (18816), pp. 255-259, pi. 16, fig. 72. 

 Pohjkrikos, Delage and Herouard (1896), p. 386, fig. 679. 

 Polykrikos, Calkiu.s (1901), p. 140. 

 Polykrikos, Lang (1901), p. 23. 

 Polykrikos, Hartog (1906), pp. 110, 131, 132. 

 Polykrikos, Kofoid (1907&), pp. 291-293, fig. 1. 

 Polykrikos, Paulsen (1908), pp. 106, 107, fig. 149. 

 Pohjkrikos, Poche (1913), p. 162. 



Polykrikos, Chatton (1914c), pp. 157-194, figs. 1-13; pi. 9, figs. 1-14. 

 Polykrikos, West (1916), pp. 54, 79, fig. 39. 



Diagnosis 



Polykrikidae of 2, 4, or 8 zooids in chain, each zooid with a GymnodiniHm 

 type of structure, girdle a descending left spiral of 1 turn; sulcus extending 

 the whole length of the l)ody and continuous with that of the adjacent zooids, 

 each zooid having the same orientation. Number of nuclei is usually less than 

 that of the zooids, generally in a ratio of 1 to 2. Nematocysts present ; surface 

 of h^qoocone ribbed or smooth; holozoic nutrition. Plasma colored, without 

 pigment. Length of chain of 4 zooids, 215^. Marine, eupelagic and neritic, 

 and from warm temperate waters. Two species. 



Organology 



The individual zooids of PoJi/Jin'kos differ liut little from many species of 

 the genus Gjimnodiuinm, their colonial hal)it and the presence of nematocysts 

 alone separating them from that genus. The body of the colony as a whole is 



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