_Natural vectors._--Cockroaches, Venezuela (Tejera, 1926). Order HYPERMASTIGINA Family HOLOMASTIGOTIDAE =Leptospironympha eupora= Cleveland et al. _Natural host._--_Cryptocercus punctulatus_, U.S.A., Appalachian area (Cleveland et al., 1934). =Leptospironympha rudis= Cleveland et al. _Natural host._--_Cryptocercus punctulatus_, U.S.A., Appalachian area (Cleveland et al., 1934). =Leptospironympha wachula= Cleveland et al. _Natural host._--_Cryptocercus punctulatus_, U.S.A., Appalachian area (Cleveland et al., 1934). =Macrospironympha xylopletha= Cleveland et al. _Natural host._--_Cryptocercus punctulatus_, U.S.A., Appalachian area (Cleveland et al., 1934). Family LOPHOMONADIDAE =Lophomonas blattarum= Stein _Natural hosts._--_Blatta orientalis_, Czechoslovakia (Stein, 1860); Germany (Bütschli, 1878; Schubotz, 1905; Chen, 1933); U.S.A. (Leidy, 1879a; Kudo, 1922, 1925, 1926, 1926b; McAdow, 1931); Europe (Janicki, 1908); U.S.S.R. (Yakimov and Miller, 1922; Zasukhin, 1930); Poland (Lorenc, 1939). _Blattella germanica_, U.S.A., Ohio (McAdow, 1931). _Blattella germanica_ and/or _Periplaneta americana_, Egypt (DeCoursey and Otto, 1956, 1957). _Periplaneta americana_, England (Schuster, 1898); Europe (Janicki, 1910); U.S.A. (Kudo, 1926b; McAdow, 1931; Hatcher, 1939; Armer, 1944); Philippine Islands (Hegner and Chu, 1930). _Periplaneta_ sp., Goa (Mello and Lima Ribeiro, 1924, 1925). "Küchenschaben," Austria (Bělǎr, 1916). The protozoan (fig. 2, E) is found in the host's colon, particularly anterior portion; encysted stages of organism are found throughout hind gut. Of 1,400 _B. orientalis_ studied, 32 percent harbored this organism (Kudo, 1925, 1926). Yakimov and Miller (1922) found 7 percent of 124 _B. orientalis_ infested. Zasukhin (1930) found 10 percent of over 3,000 _B. orientalis_ infested. The flagellate does not harm the host and is never present in the host tissue; it should be considered a commensal (Kudo, 1926). =Lophomonas striata= Bütschli _Synonymy._--_Lophomonas sulcata_ Schuster is most probably identical with _L. striata_ (Kudo, 1926b). _Natural hosts._--_Blatta orientalis_, Germany (Bütschli, 1878; Schubotz, 1905); Europe (Janicki, 1908, 1910); U.S.A. (Kudo, 1922, 1926, 1926b; McAdow, 1931); U.S.S.R. (Yakimov and Miller, 1922; Zasukhin, 1930); Poland (Lorenc, 1939). _Blattella germanica_, U.S.A., Ohio (McAdow, 1931). _Blattella germanica_ and/or _Periplaneta americana_, South Africa (Porter, 1930). _Periplaneta americana_, Indochina (Weill, 1929); Philippine Islands (Hegner and Chu, 1930); U.S.A. (Kudo, 1926b; McAdow, 1931; Armer, 1944). Cockroach, Venezuela (Tejera, 1926); England or U.S.A.? (Lucas, 1928). "Küchenschaben," Austria (Bělǎr, 1916).