230 



PROTOZOOLOGY 



Fig. 104. a, b, Polykrikos kofoidi (a, colony of four individuals, 

 X340; b, a nematocyst, X1040) (Kofoid and Swezy); c, Peridinium 

 tabulatum, X460 (Schilling); d, P. diver gens, X340 (Calkins); e, Cera- 

 tium hirundinella, x540 (Stein); f, C. longipes, XlOO (Wailes); g, C. 

 tripos, Xl40 (Wailes); h, C. fiisus, XlOO (Wailes); i, Heterodinium 

 scrippsi, X570 (Kofoid and Adamson). 



fresh or salt water. Numerous species; specific identification is 

 difficult due to a great variation (p. 162). 



