A Fin Whale was cast ashore on the coast of Pulu Sugi, one of the smaller islands of the Rhio Archipelago between Singapore and the Sumatran coast in July 1936. Thanks to the generosity of Dr. K. W. Dammerman, former Director of 's Lands Plantentuin at Buitenzorg, and the unvaluable help of the late Mr. F. N. Chasen, Director of the Raffles Museum, Singapore, the specimen was saved and after cleaning sent to the Rijksmuseum van Natuurlijke Historie, Leiden. It was received in June 1939. The length of the skeleton was slightly over 12 m and it must have belonged to an adult specimen, for in all vertebrae the epiphyses are coalesced completely with the rest of the vertebral body (Wheeler, 1930). It was clear that the specimen belonged to a Balaenoptera. It was too large for a B. acutorostrata and too small for a B. physalus and nearly related to B. borealis, but there were some important characters in which it differed from this species. The preliminary examination showed that especially the flat rostrum, the form of the part of the skull between the palatine bones and the occipital condyles were markedly different and also that the form of the atlas and the backward direction of the spinous processes of the dorsal and lumbar vertebrae did not agree with borealis. All these characters pointed to B. edeni, a species from the Indian region still insufficiently known, and also to B. brydei, though the latter was only known from South African waters. The stranding of the Pulu Sugi Whale offered a good opportunity to make a close comparison of edeni and brydei and if possible to clear up the relation between these two species. B. edeni was described by Anderson (1878), who gave a description of the skeleton from a specimen stranded in Thyabu Choung off the Gulf of Martaban. B. brydei was