432 PROTOZOOLOGY 



spores 17-25/x by 8-19/i; in Lumbricus ruhellus, L. castaneus and 

 Helodrilus foetidus. 



M. lumbrici Henle (Fig. 202, d, e). Sporadins about 200^ by 

 60-70m; cysts about 162/i in diameter; in Lumbricus terrestris, L. 

 ruhellus, and L. castaneus. 



Genus Apolocystis Cognetti. Trophozoites spherical; without 

 principal axis marked by presence of any special peripheral organ; 

 solitary; spore biconical; in seminal vesicles or coelom of various 

 oligochaetes. Many species. 



A. gigantea Troisi (Fig. 202, /). In seminal vesicles of Helodrilus 

 foetidus and Lumbricus rubellus; late October to March only; fully 

 grown trophozoites 250-800/i in diameter; whitish to naked eyes; 

 pellicle thickly covered by 10-15/x long 'hairs'; endoplasm packed 

 with spherical paraglycogen grains (3/^ in diameter); nucleus 35- 

 43/1 in diameter; cysts 40O-800yu in diameter; spores 19/1 by 8.6/1. 



A. minuta Troisi (Fig. 202, g). In seminal vesicles of Lumbricus 

 terrestris, L. castaneus and L. rubellus; mature trophozoites 40- 

 46/i in diameter; endoplasm yellowish brown, packed with spherical 

 paraglycogen grains (5.3-7/x in diameter); nucleus 10/t in diameter; 

 cysts 68-74/t by 55-65/i; spores of 3 sizes, 11/i by 5.5/i, 18.8/t by 7n 

 and 21.6/1 by 9.8/1. 



Genus Nematocystis Hesse. Trophozoites elongate, cylindrical 

 and shaped like a nematode; solitary. Many species. 



N. vermicularis H. (Fig. 202, h). In seminal vesicles of Lumbricus 

 terrestris, L. rubellus, Helodrilus longus, Pheretima barbadensis; 

 trophozoites 1 mm, by lOO/i; cylindrical, both ends with projections; 

 nucleus oval; endoplasm alveolated, with paraglycogen grains; 

 sporadins become paired lengthwise; cysts and spores unknown. 



Genus Rhabdocystis Boldt. Trophozoites elongate, gently curved; 

 anterior end swollen, club-shaped; posterior end attenuated; spores 

 with sharply pointed ends. One species. 



R. claviformis B. (Fig. 202, i, j). In seminal vesicles of Octolasium 

 complanatum; sporadins extended, up to 300/t by 30/t; pellicle dis- 

 tinctly longitudinally striated; zooamylon bodies 2-4/t in diameter; 

 cysts biscuit-form, 110/t by 70/i; spores 16/i by 8/i. 



Genus Enterocystis Zwetkow. Early stages of trophozoites in 

 syzygy; sporadins in association ensiform; cysts spherical without 

 ducts; spores elongate ovoid, with 8 sporozoites; in gut of ephemerid 

 larvae. 



E. ensis Z. (Fig. 202, k, I). Sporadins in syzygy 200-510/t long; 

 cysts 200-350/£ in diameter; spores elongate ovoid; in gut of larvae 

 of Caenis sp. 



