UNCLASSIFIED PROTISTS OF ARTHROPODS - THE ULTRASTRUCTURE OF NEPHRIDIOPHAGA-PERIPLANETAE (LUTZ AND SPLENDORE, 1903) N-COMB, AND THE AFFINITIES OF THE NEPHRIDIOPHAGIDAE TO OTHER PROTISTS

Observations by electron microscopy were conducted on Coelosporidium p eriplanetae (Lutz and Splendore, 1903) Swarczewsky, 1914, an extracell ular sporogenic protist in the lumen of the Malpighian tubules of Blat ta orientalis Linn., 1758 and other domiciliary cockroaches. Results g enerally agreed with earlier studies by light microscopy but also allo wed a more complete characterization of the species. Some outstanding features of the protist were: amoeboid multinucleate stages (plasmodia ) capable of producing cytoplasmic projections for attachment to micro villi of tubules, endogenous formation of spores, differentiation of ' 'generative'' and ''somatic'' nuclei in plasmodia undergoing spore for mation, polarized early sporoblasts (a nucleus on one half and a chond riome on the other), and biconcave, ovoid, non-polarized spores that a re retained until maturation by the plasmalemma and residual cytoplasm of the original plasmodium. The new combination Nephridiophaga peripl anetae is proposed based on this new, updated information. The family name Nephridiophagidae Sprague, 1970 is resurrected to include N. peri planetae and eleven other species of protists in the Malpighian tubule s of arthropods, mostly insects in the orders Dictyoptera and Coleopte ra. According to its characteristics, the family Nephridiophagidae can not be included into any of the currently recognized phyla of protists . It is suggested that it should be temporarily treated as an incertae sedis group of Protista.