178 HANDBOOK OF PROTOZOOLOGY 



to the Mycetozoa. Without any skeletons. Their hfe history is 

 not well known. Flagellate swarmers and encysted stages occur 

 commonly. The majority of the Proteomyxa lead parasitic life 

 in fresh-water algae or green plants. 



Three families and several genera are usually distinguished 

 in this order. 



Individuals often fused into pseudoplasmodium Family 1 Labyrinthulidae 



Solitary and Heliozoa-like 



With flagellated swarmers Family 2 Zoosporidae 



Without flagellated swarmers Family 3 Vampyrellidae 



Family 1 Labyrinthulidae Haeckel 



The body is a small fusiform protoplasmic mass. Several 

 individuals are grouped in a network of sparingly branched and 

 anastomosing filopodia. Multiplication by fission. Under un- 

 favorable conditions individuals encyst independently. Flagel- 

 lated stage may or may not be present. Two genera. 



Genus Labyrinthula Cienkowski. Minute forms feeding on 

 various species of algae of both fresh and salt waters. Often 

 brightly colored due to the chlorophyll bodies taken in as food. 



Labyrinthula cienkowskii Zopf (Fig. 67, a). Attacks the 

 fresh-water alga, Vaucheria. 



Genus Labyrinthomyxa Duboscq. Body fusiform, amoeboid 

 and flagellate phases variable in size. The flagellated stage pene- 

 trates through the host cell membrane. 



Labyrinthomyxa sauvagea lit Duboscq (Fig. 67, 6-e). Fusiform 

 bodies 7 to 11 microns long. Pseudoplasmodium formed. 

 Amoeboid stage measures 2.5 to 14 microns; flagellate stage 7 

 to 18 microns long. Parasitic in Laminaria lejolisii at RoscofT, 

 France. 



Family 2 Zoosporidae Zopf-Delage 



Body form irregular, but with radiating filopodia. The 

 general appearance is somewhat like a heliozoan. Swarmers. 



Genus Pseudospora Cienkowski. Body minute. Parasitic in 

 algae and Mastigophora (including Volvocidae). The organism 

 nourishes itself on the protoplasm of the host, grows, and multi- 

 plies into a number of smaller individuals by repeated division. 



