330 PROTOZOOLOGY 



together within a tough, opaque membrane. The growth is the best 

 at 14-24° C. and at 12-22 per cent chlorinity. 



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. 154, h-e). Fusiform body 7-1 Iju long; pseu- 

 doplasmodium-formation; amoeboid stage 2.5-14)u long; flagellate 

 stage 7-18m 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, b}^ repeated division; the latter biflagellate, seek a new 

 host, and transform themselves into amoeboid stage; encystment 

 common. 



P. volvocis C. (Fig. 154, /, g). Heliozoan form about 12-30^ in 

 diameter; pseudopodia radiating; cysts about 25)u in diameter; in 

 species of Volvox. 



P. parasitica C. Attacks Spirogyra and allied algae. 



P. eudorini Roskin. Heliozoan forms 10-12/i 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 bi- 

 flagellate swarmers which become amoeboid and unite to form 

 pseudoplasmodium; fresh or salt water. 



P. amyli C. (Fig. 154, 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 proto- 

 plasmic contents; body often reddish because of the presence of 

 carotin; multinucleate; multiplication in encysted stage into uni- or 

 multi-nucleate bodies; cysts often also reddish. 



Genus Vampyrella Cienkowski. Heliozoa-like; endoplasm vacuo- 

 lated or granulated, with carotin granules; numerous vesicular 

 nuclei and contractile vacuoles; multinucleate cysts, sometimes 

 with stalk; 50-700^ in diameter. Several species. 



V. lateritia (Fresenius) (Fig. 154, k, I). Spherical; orange-red 

 except the hyaline ectoplasm; feeds on Spirogyra and other algae 



