Observations on two new species of Monocystis Stein, 1848 (Protozoa: Apicomplexa: Monocystidae) Monocystis darjeelingensis sp.n. and M. ranaghatensis sp.n. from earthworms (Annelida: Oligochaeta) of West Bengal, India

Surveys of acephaline gregarines infesting earthworms from Senchal of Darjeeling and Ranaghat of Nadia districts of West Bengal, India revealed the occurrence of two new species of Monocystis Stein, 1848. Monocystis darjeelingensis sp.n. was found in the coelomic fluid of the earthworm Amynthus robusta Perrier, 1892 from Senchal, Darjeeling, and M. ranaghatensis sp.n. in the seminal vesicles of the earthworm Eutyphoeus valtoni (Michaelsen) from Ranaghat. Trophozoites of M. darjeelingensis sp.n. are cylindroid in shape: 210.0-273.0 (231.0 +/- 2.0) x 84.0-140.0 (98.0 +/- 1.8) mu m; spherical gametocyst: 147.0-163.0 (156.0 +/- 0.4) mu m; navicular oocyst: 15.4-18.0 (17.0 +/- 1.0) x 8.0-9.0 (8.2 +/- 0.5) mu m. Trophozoites of M. ranaghatensis sp.n. are napiform, having a nearly spheroid to ellipsoid or ovoid body, 119.0-167.0 (124.0 +/- 11.0) x 57.0-84.0 (62.0 +/- 1.9) mu m with a prominent tail like structure at the posterior end and ellipsoidal nucleus, 9.0-22.0 (12.0 +/- 0.4) x 9.0-13.0 (10.0 +/- 1.5) mu m. Gametocysts are egg-shaped, measuring 95.0-124.0 (105.0 +/- 0.9) mu m. Oocysts are biconical, measuring 7.6-10.1 (9.3 +/- 1.1) x 4.1-5.6 (4.5 +/- 1.3) mu m.