Though we know already a rather large number of Polychaetous Annelids from the Caribbean Sea, hitherto, as far as I know, no Annelids have been described from the coast of the island Curaçao and I therefore was very glad, that my colleague Dr. VAN DER HORST kindly placed in my hands for identification a collection of Annelids, made during his stay on that island in the summer of 1920. The worms have been collected in „de Spaansche haven”, „het Spaansche water” and the „Caracas-baai” at the South-coast of the island. Our first knowledge of the West-indian Annelids dates from the middle of the foregoing century when Oersted (1845—48), Kroyer and Schmarda travelled in Central and South America. The Annelids procured by the first two naturalists have been examined by Grube and were described under the title of „Annulata Oerstediana” ¹). Schmarda during his journey around the world (1853—57) in the summer and autumn of 1855 stayed in Jamaica (Kingston and Port royal) and on the coral-reef of the neighbouring Keys; in 1857 he visited Havannah and St. Thomas ²). The Challenger-expedition in 1873 in shallow-water off St.Thomas and between tide-marks collected a half dozen of Annelids ³). The largest collection of Annelids however was made during the dredgings of the U. S. Coast survey steamer „Blake” under the direction of POURTALÈS during the years 1868—70 and of ALEX. AGASSIZ from 1877 to 79 in the Gulf of Mexico and in the Caribbean Sea; they have been examined and described by ERNST EHLERS 4) and HERMANN AUGENER 5). In 1902 AARON TREADWELL described the Polychaetes collected by the expedition sent to Porto Rico in the winter of 1898—99 by the U. S. commissioner of Fish and Fisheries 6); in 1911 the same naturalist published a paper on the Polychaetous Annelids from the Dry Tortugas, Florida 7) and in 1917 on Polych. Annelids from Florida, Porto Rico, Bermuda and the Bahamas 8). In 1919 Ruth Hoagland described the polychaetous Annelids from Porto Rico, the Florida Keys and Bermuda, collected by the expeditions sent out in 1914 and 1915 by the American Museum of Nat. History and the New York Academy of Sciences in cooperation with the Government of Porto Rico 9).