On modern cargo ships cockroaches are reported to be extremely numerous in the galley, the crew's quarters, and sometimes in the holds; they dwell in hot, humid environments such as the casing around steam pipes (Monro, 1951). Williams (1931) reported that _Blattella germanica_ was the most important cockroach pest on ships seen at New York. Although often numerous in the holds, the cockroaches as a rule congregated in living quarters. They were also frequently found between tarpaulins covering the hatches. It was not unusual to kill 20,000 to 50,000 in the forecastle, and more than 20,000 have been taken from a single stateroom. Simanton (1946) inspected the S.S. _William Kieth_ when it berthed at San Francisco from a 10-month voyage to the South Pacific. The holds were infested with thousands of _Periplaneta americana_, but in the crew's quarters, mess halls, and storerooms _B. germanica_ predominated. After insecticidal treatment about 2,000 _P. americana_ were seen in each hold and as many as 24 _B. germanica_ in each cabin. Richardson (1947) reported that in Army transports inspected between 1943 and 1946 at New York, _P. americana_ was found in the galleys and messes, and occasionally heavy infestations were found deep in the holds; _B. germanica_ was found in the galleys and messes; _Blatta orientalis_ was found only in the hold. Additional references indicating the presence of _Blattella germanica_ on ships may be found in the account of its parasite _Ripidius pectinicornis_ (p. 232). Although Rice (1925) and Williams (1931) cite _B. germanica_ as the most numerous cockroach on ships, Brooke (1920) stated that the great majority of ship cockroaches were _Periplaneta americana_. In addition to citing cockroach infestations on ships, the following authors reported various methods for disinfecting ships: Canalis (1916), Pryor (1918), Brooke (1920), Rice (1925), Williams (1931), Simanton (1946), Richardson (1947), and Anonymous (1951, 1954). COCKROACHES ASSOCIATED WITH SHIPS In the following list we include some previously unpublished data on cockroaches that were recovered from ships at the Miami, Fla., Quarantine Station for the periods November 1945 through May 1946; May, June, August, and September 1950; and 17 July 1957 (Porter, personal communication, 1958). These data were lumped, without breakdown to species, under the entry Orthoptera in Porter (1958). Certain of the species listed below occur only accidentally on shipboard and will probably never establish breeding colonies on ships or become pests on shipboard or elsewhere; some were merely passengers between one land-based colony and another. Others, the truly domiciliary pests, are as likely to be pests on shipboard as they are in land-based structures. =Blaberus discoidalis= _Hispaniola._--On board ship (Rehn and Hebard, 1927). =Blatta orientalis= _U.S.A._--At Port of New York (Richardson, 1947). =Blattella germanica= _At sea?_--In ships casks (Chamisso, 1829).