In the second half of the nineteenth century an important contribution to our knowledge of the fauna of the Netherlands Antilles, and especially of St. Martin, was made by the medical officer of that island, H. E. VAN RIJGERSMA, whose name, however, has remained almost unknown to Dutch biologists. By assembling important zoological collections VAN RIJGERSMA enabled specialists to study the fauna of St. Martin and the neighbouring islands; as a result, this fauna was for a long time better known than that of many other West Indian islands. From information kindly placed at my disposal by the Rijksarchief (Netherlands State Archives) and the Record Office of the Ministerie van Zaken Overzee (Netherlands Ministry of Affairs Overseas) it appears that HENDRIK ELING (or ELINGSZ.) VAN RIJGERSMA was born in 1834 or at the beginning of 1835, and was very probably of Frisian origin. It is not known where he studied; but he practised on the island of Marken, in the Netherlands, as doctor, surgeon and obstetrician, until the year 1863. By Royal Decree No. 60, dated 26 June 1863, VAN RIJGERSMA was appointed Government Physician on the Dutch West Indian island of St. Martin, where he went in the autumn of 1863 with his wife and two children. He filled this post on St. Martin until his death on 4 March 1877, only once returning on furlough to the Netherlands, from Spring 1873 till March 1874. He was married to MARIA HENRIETTA GRÄFING, probably from Amsterdam. At his death he left seven children. His widow continued to live on St. Martin until 1893, when she went back to the Netherlands with five of her children.