Stenophora juli (Frantzius, 1848) Labbé, 1899, Sporozoa parasite of the Diplopoda Rhinocrius padbergi Schubart, 1930, were examined by light and electron microscopy. As a result of a cytochemical investigation, similar content to those obtained by other authors has been shown. Ultrastructure of membrane shows complex microscopic longitudinal folds and among this folds there are pores for mucous secretion. An unknown layer was found under the membrane and upon the mioneme. The sept which divide this protozoa in protomerite and deutomerite is formed by a large mionem, in which a great number of mitochondria has been shown. Paraglicogene granules appear present in large quantity in the endoplasm, and lipid inclusion appear in smaller quantity. Mitocondria, endoplasmic reticulum and Golgi complex are also observed in the endoplasm. The nuclear envelope shows a double-layered structure with pores and the nucleolus has a granular aspect, containing several vacuoles.