The halacarid fauna of the eastern North Atlantic Ocean and its adjacent waters, the Mediterranean, the North Sea, and the Baltic, has been studied and described in more than 100 papers; but only a few papers deal with the halacarid fauna on the east coast of the United States and the Caribbean area. Twenty-three halacarids are recorded from the Caribbean and the Gulf region, compared to 75 from the Mediterranean Sea. In samples collected in shallow waters in the Gulf of Honduras and off Nicaragua and Panamá, halacarids were present in low numbers. Several of the species found are new to science. In this paper, Copidognathus manubriatus Viets, 1936 is redescribed, and descriptions of Copidognathus lepidoides n.sp., C. nemenus n.sp. and C. modestus n.sp. are given.