290 PROTOZOOLOGY 



L. cienkowshii Zopf (Fig. 133, a). Attacks Vaucheria in frosli 

 water. 



L. sp. Renn. Renn (1934, 1936) found in the diseased leaf tissue 

 of the eel-grass, Zostera marina, whose leaves showed 'spotting 

 and darkening,' a species of Labyrinthula; fusiform with termi- 

 nal, often branching, filopods; frequently in network by associa- 

 tion of many individuals; infected host cell is completely 

 destroyed; Atlantic coast. 



Genus Labyrinthomyxa Duboscq. Body fusiform; amoeboid 

 and flagellate phases, variable in size; flagellate stage penetrates 

 the host cell membrane; in plants. 



L. sauvageaui D. (Fig. 133, b-e). Fusiform body 7-1 l/z long; 

 pseudoplasmodium-formation; amoeboid stage 2.5-14/i long; 

 flagellate stage 7-18^ long; parasitic in Laminaria lejolisii at 

 Roscoff, France. 



Family 2 Pseudosporidae Berlese 



Genus Pseudospora Cienkowski. Body minute; parasitic in 

 algae and Mastigophora (including Volvocidae); organism 

 nourishes itself on host protoplasm, grows and multiplies into a 

 number of smaller individuals, by repeated division; the latter 

 bifiagellate, seek a new host, and transform themselves into 

 amoeboid stage; encystment common. 



P. volvocis C. (Fig. 133, /, g). Heliozoan form about 12-30^ 

 in diameter; pseudopodia radiating; cysts about 25/x in diameter; 

 in species of Volvox. 



P. parasitica C. Attacks Spirogyra and allied algae. 



P. eudorini Roskin. Heliozoan forms 10-12^ in diameter; 

 radiating pseudopodia 2-3 times longer; amoeboid within host 

 colony; cysts 15/x in diameter; in Eudorina elegans. 



Genus Protomonas Cienkowski. Body irregularly rounded with 

 radiating filopodia; food consists of starch grains; division into 

 bifiagellate swarmers which become amoeboid and unite to 

 form pseudoplasmodium; fresh or salt water. 



P. aniyli C. (Fig. 133, h-j). In fresh water. 



Family 3 Vampyrellidae Doflein 



Filopodia radiate from all sides or formed from a limited area; 

 flagellate swarmers do not occur; the organism is able to bore 

 through the cellulose membrane of various algae and feeds on 



