318 PROTOZOOLOGY 



vision (Calkins, 1898); morphology and physiology (Goor, 1918; 

 Kofoid, 1920; Pratje, 1921); feeding (Hofker, 1930); luminescence 

 (Harvey, 1952). 



Genus Pavillardia Kofoid and Swezy. Annulus and sulcus similar 

 to those of Gymnodinium; longitudinal flagellum absent; stout 

 finger-like mobile tentacle directed posteriorly; salt water. One 

 species. 



P. tentaculifera K. and S. 58m by 27/x; pale yellow; off California. 



Family 5 Gymnodiniidae Kofoid 



Naked forms with simple but distinct 1/2-4 turns of annulus; 

 with or without chromatophores; fresh or salt water. 



Genus Gymnodinium Stein. Pellicle delicate; subcircular; bi- 

 laterally symmetrical; numerous discoid chromatophores vari- 

 colored (yellow to deep brown, green, or blue) or sometimes absent; 

 stigma present in few; many with mucilaginous envelope; salt, 

 brackish, or fresh water. Numerous species (Schiller, 1928a) ; culti- 

 vation and development (Lindemann, 1929). 



G. aeruginosum S. (Fig. 129, a). Green chromatophores; 20-32/x by 

 13-25/x (Thompson, 1950) ; ponds and lakes. 



G. rotundatum Klebs (Fig. 129, b). 32-35/x by 22-25 M ; fresh water. 



G. palustre Schilling (Fig. 129, c). 45/z by 38^; fresh water. 



G. agile Kofoid and Swezy (Fig. 129, d). About 28m long; along 

 sandy beaches. 



Genus Hemidinium Stein. Asymmetrical; oval; annulus about 

 half a turn, only on left half. One species. 



H. nasutum S. (Fig. 129, e). Sulcus posterior; chromatophores 

 yellow to brown; with a reddish brown oil drop; nucleus posterior; 

 transverse fission; 24-28ju by 16-17/x; fresh water. 



Genus Amphidinium Claparede and Lachmann. Form variable; 

 epicone small; annulus anterior; sulcus straight on hypo cone or also 

 on part of epicone; with or without chromatophores; mainly holo- 

 phytic, some holozoic; coastal or fresh water. Numerous species 

 Schiller, 1928a). 



A. lacustre Stein (Fig. 129, /). 30/t by 18/x; in fresh and salt (?) 

 water. 



A. scissum Kofoid and Swezy (Fig. 129, g). 50-60m long; along 

 sandy beaches. 



A. fusiforme Martin. Fusiform, twice as long as broad: circular 

 in cross-section; epicone rounded conical; annulus anterior; hypo- 

 cone 2-2.5 times as long as epicone; sulcus obscure; body filled with 



