A representative of the rare genus Tetrapocillon Brondsted (1924) was found for the first time in the Atlantic Ocean, dredged at 70 m depth during the recent CANCAP VII Expedition to the Cape Verde Islands. The single specimen differed from the previously known Indo-Pacific specimens of the genus ( T. novaezealandiae Brondsted, 1924) in the life colour, the possession of thin strongyles (in stead of thicker styles) and the smaller size of the tetrapocilli. For these reasons and the geographic disjunction the Cape Verde specimen was assigned to a new species, T. atlanticus n.sp. The affinities of the genus Tetrapocillon and other genera, seemingly related on the basis of similarities in the microsclere complement are discussed; it is made apparent that it is closest to Guitarra and Coelodischela. In spite of the suggestion provided by the microsclere names Tetrapocillon and Iophon are not closely related.