Entamoeba thomsoni Lucas
Synonymy.—Endamoeba thomsoni [Kudo, personal communication, 1957].
Natural hosts.—Blatta orientalis, England (Lucas, 1927a, 1928); U.S.A. (Taliaferro, 1928; McAdow, 1931); U.S.S.R. (Zasukhin, 1930); Germany (Chen, 1933).
Blattella germanica, U.S.A. (McAdow, 1931).
Periplaneta americana, England (Lucas, 1927a); U.S.A. (Smith and Barret, 1928; McAdow, 1931); Philippine Islands (Hegner and Chu, 1930).
The organism is found in the hind intestine and rectum of the cockroach. Smith and Barret (1928) developed a synthetic medium in which cultures of E. thomsoni were carried through successive transfers for 24 months.