As a part of an ongoing biodiversity survey of aseptate greg
arine fauna of oligochaete hosts of West Bengal, an expedition
was carried out in the Darjeeling district of West Bengal and most
of the earthworms collected were found to be infested with a
species
of
Monocystis
Stein, 1848. The monocystid species was collected from the se
minal vesicles of the earthworm and was identified as a
new species,
Monocystis amynthae
sp. nov. The gamont of the new species is ch
aracterized by having an elongated body with broad
anterior end, separated from the narrow posterior end by a promin
ent constriction measuring 49.0-77.0 (66.0±1.3) μm x 32.0-41.0
(37.0±2.8) μm. The gametocysts are oval-shaped, measuring