In April 1898 the veliid genus Trochopus Carpenter was erected to hold a new halophilous water-strider from Jamaica, described as marinus. The specimens were netted in numbers on standing salt waters beneath mangrove trees in swamps near the head of Kingston Harbour. In August of the same year CHAMPION described the second member of the genus, Trochopus salinus, collected in the mangrove swamps of the Pearl Islands, Gulf of Panama. Subsequently, KIRKALDY (1900) wrongly considered the genus Trochopus to be a synonym of Rhagovelia Mayr (1865), but correctly treated the trivial name marinus as a synonym of Rhagovelia plumbea Uhler. This generic synonymy was largely accepted until CHINA & USINGER (1949) took Trochopus out of synonymy and restored it to its original status. As the trivial synonymy is correct, this makes the genotype Trochopus plumbeus (Uhler) (= marinus Carpenter). Recently BACON (1956) and also MATSUDA (1956) followed KIRKALDY and wrongly repudiated Trochopus as a synonym of the older genus Rhagovelia, including the transfer of plumbeus and salinus back into the latter genus. In the present paper, the authors are in full concurrence with the classification of CHAMPION and of CHINA & USINGER, in which Trochopus is restored to its original status. As here systematized, Trochopus comprises T. plumbeus, T. salinus, and the new species described below from Surinam.