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Record: oai:ARNO:508458

AuthorF.A. Jentink
TitleOn Gymnura candida
JournalNotes from the Leyden Museum
AbstractIt is a fact long since known to Naturalists, that there are among the Gymnura rafflesii-specimens many albinos, but a few weeks ago visiting several Musea of Natural History, I was greatly surprised to find that all these albino-specimens were from Borneo, and that none of the collections I examined contained either a so called albino from Sumatra or from Malacca, or a dark colored specimen from Borneo. Professor Schlegel in his book entitled “Handleiding tot de beoefening der Dierkunde, 1857, Deel I”, says “In the Borneo-specimens of Gymnura rafflesii the “whole body is variegated with white”, and Dr. Günther, P. Z. S. L. 1876, p. 425, speaking from the Borneo-form, which he distinguished s. n. Gymnura rafflesii, var: candida states, »all the specimens received from Labuan dif“fer from the typical form in being of a white colour, “only a part of the longest and strongest hairs on the “trunk being black. The head, legs and tail are pure “white. As no structural differences can be discovered “either in the skull, or dentition, or any other part of “the body, I consider it sufficient to distinguish this form “as a merely local variety.” As I returned home I examited what we possess in our collection of the named species and found two dark colored specimens, one from Sumatra, Padang-bessie, collected by the late S. Müller, the other from Malacca and an albino-specimen from Borneo, many years ago sent over by the late Dr. Schwaner; and further two complete skeletons, one of the Sumatra-specimen, the other of the Borneo-individual. In comparing these skeletons I soon saw that they presented many differences and now, having closely studied and compared them, I do not hesitate to say that we have here to do with two distinct species. I will shortly explain the differences, which I have observed. In the skull of the Borneo-specimen the molars and canines have not yet attained their full growth, while in the other all the teeth are well developed, and although the former must for this reason be regarded as a younger individual, it is nevertheless larger and its skeleton is much stouter in all its forms and dimensions. In both of them the number of vertebra and costae is the same, viz: 15 dorsales with 15 ribs, 5 lumbares, 5 sacrales and 26 caudales. The skull of the Borneo-specimen is of a more elongate form, and less broad than in the Sumatra-specimen.
Document typearticle
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