MORPHOLOGY AND TAXONOMY OF MASTIGOPHORA 303 



2. Girdle and sulcus obscure; flagella thread- 



like Family 1. Protodiniferid.^ 



Girdle and sulcus distinct; transverse 

 flagellum ribbon-like 3 



3. Individuals permanently colonial Family 3. Polykrikid.e 

 Individuals not colonial 4 



4. With ocellus Family 5. Pouchetiid.e 



Without ocellus 5 



5. With tentacle Family 4. Noctilucid.e 



Without tentacle 6 



6. Not parasitic Family 2. Gymnodiniid.e 



Parasitic Family 6. Blastodinid^ 



Family 1. Protodiniferidae. 



1. Flagellum encircling tentacle-like process. . 2 



Girdle short ; tentacle not encircled . . Genus Protodinifer 



2. Both flagella wound about conical tentacle 



Genus Hemistasia 



Both flagella free Genus Oxyrrhis 



Family 2. Gymnodiniidse. 



1. Girdle one-half turn only Genus Hemidinium 



Girdle more than one-half tiu-n 2 



2. Girdle anterior; epicone relatively minute 



Genus A mphidinium 

 Girdle median, sub-median, or spirally 

 wound 3 



3. Girdle sub-median Genus Gymnodinium 



Girdle posterior or spirally wound 4 



4. Girdle posterior Genus Torodinium 



Girdle spirally wound 5 



5. Spiral girdle less than one and one-half 



turns .... Genus Gyrodinium 



Spiral one and one-half or more turns 



Genus Cochlodinium 

 Family 3. Polykrikidae. 



One genus with characters of family. . .Genus Polykrikos 

 Family 4. NoctUucidae. 



Gymnodinium-like girdle persistent .... Genus PaviUardia 

 Girdle in swarm-spore stage; adult with ten- 

 tacle Genus Nodiluca 



Family 5. Pouchetiidae. 



1. Girdle as in Gymnodinium, no displace- 



ment Genus Protopsis 



Girdle spirally wound 2 



2. With nematocysts Genus Nematodiniuin 



Without nematocysts 3 



3. Without posterior tentacle. . Genus Pouchetia 

 With posterior tentacle 4 



4. Epicone and hvpocone nearly equal . Genus Proterythropsis 

 Epicone smaller than hypocone Genus Erythropsis 



Family 6. Blastodinidse. 



1. Ectoparasitic forms on eggs or appendages 2 

 Endoparasitic forms in gut or body cavity 7 



2. Parasites on appendages of pelagic animals 3 

 Parasites on eggs or in other protozoa .... 5 



3. Hemispheres sub-equal 4 



Anterior hemisphere more developed than 



posterior Genus Oodinium 



