_Natural host._--_Periplaneta americana_, Brazil (R. de Almeida Cunha _in_ Pinto, 1919; Cunha, 1919). =Gregarina ohioensis= Semans _Natural host._--_Parcoblatta virginica_, U.S.A., Ohio (Semans, 1939): The protozoan was present in large numbers in the insect's midgut. =Gregarina panchlorae= Frenzel _Natural host._--_Panchlora exoleta_, Argentina (Frenzel, 1892): Midgut. =Gregarina parcoblattae= Semans _Natural hosts._--_Parcoblatta pensylvanica_ and _Parcoblatta uhleriana_, U.S.A., Ohio (Semans, 1939): Midgut. =Gregarina rhyparobiae= J. M. Watson _Natural host._--_Leucophaea maderae_, Uganda (Watson, 1945): Midgut. Trophozoites could be seen in sections attached to cells of the intestinal wall (fig. 2, H). =Gregarina sandoni= Harrison _Natural host._--_Melanosilpha capensis_, South Africa (Harrison, 1955): This gregarine was found in the anterior and middle parts of the mesenteron and in the hepatic caeca. =Gregarina thomasi= Semans _Natural host._--_Parcoblatta pensylvanica_, U.S.A., Ohio (Semans, 1939): Enteric caeca and midgut. =Protomagalhaesia serpentula= (de Magalhães) _Synonymy._--_Gregarina serpentula_ [Pinto, 1918a, 1919; Semans, 1943]. _Natural host._--_Periplaneta americana_, Brazil (Magalhães, 1900): In the coelom and alimentary canal. The host of this parasite (fig. 2, K) was incorrectly cited as _Blatta orientalis_ by Watson (1916). =Gamocystis tenax= Schneider (Fig. 2, L) _Natural hosts._--_Ectobius lapponicus_, France (Schneider, 1875); Germany (Wellmer, 1910, 1911; Foerster, 1938). _Ectobius pallidus_, Germany (Foerster, 1938): In intestine. Family ACTINOCEPHALIDAE =Pileocephalus blaberae= (Frenzel) _Synonymy._--_Gregarina blaberae_ [Watson, 1916]. _Natural hosts._--_Blaptica dubia_ and related forms, Argentina (Frenzel, 1892): In midgut. =Unidentified Gregarinida= _Natural hosts._--_Blaberus craniifer_, U.S.A. (Roth and Willis, unpublished data, 1953): Possibly _Diplocystis_ sp. (pl. 28, A, B). _Cryptocercus punctulatus_, U.S.A. (Cleveland et al., 1934). _Leucophaea maderae_, Philippine Islands (Hegner and Chu, 1930): In intestines of host. U.S.A. (Roth and Willis, unpublished data, 1958): Cysts in feces (pl. 28, C). _Gromphadorhina portentosa_, U.S.A., in laboratory colony (Roth and Willis, unpublished data, 1958): In intestine of adult female. _Pycnoscelus surinamensis_, Hawaii (Schwabe, 1950): A cephaline gregarine was found in the cockroach's digestive tract; it was also claimed to be present in new-born nymphs. Order COCCIDIA Family ADELEIDAE =Adelina cryptocerci= Yarwood