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Show 7fi n ON REMAINS OF GRYPOTHERIUM (NEOMYLODON) LISTAI. [Jan. 23, has shown that when bones are buried in ordinary sediments they undergo changes which gradually cause the percentage of contained fluorine to increase. According to him, the longer a bone has been buried, the greater is the percentage of fluorine found in it on analysis. In one case ' he examined the scapula of a deer and a human tibia, discovered together in fluviatile sand near Billancourt (Seine); he found that the former had 7 or 8 times its usual percentage of tluorine, while the human bone did not differ in any respect from the normal in this constituent. He therefore concluded that the latter bone was not of the same age as the former, but had been introduced comparatively recently by burial. In this and the other recorded cases, however, it is to be observed that the sediment was of a uniform character and admitted of free percolation of water. In the Patagonian cavern, on the contrary, the bones occur partly in dust, partly in dried herbage, partly in dried excrement, and partly in the burnt residue of the same. Moreover, they must always have been subjected to intense dryness, and the usual process of chemical alteration cannot have taken place. Considering all circumstances, I think that, even without chemical evidence, zoologists and geologists cannot fail now to agree with Dr. Moreno and his colleagues of the La Plata Museum, that the remarkably preserved Grypotherium from the Patagonian cavern belongs to the extinct Pampean fauna of South America and need not be searched for in the unexplored wilds of that continent. If we accept the confirmatory evidence afforded by Mr. Spencer Moore, we can also hardly refuse to believe that this great Ground-Sloth was actually kept and fed by an early race of man. EXPLANATION OF T H E PLATES. P L A T E V. Fig. 1. Grypotherium listai; hinder portion of cranium, right lateral and inferior (1 a) aspects, and in median longitudinal section (1 b), nearly one-half nat. size, b.s., basisphenoid ; f„ anterior condyloid foramen ; m., facette for stylohyal; p.s., presphenoid ; pt., pterygoid; t., tympanic. 2. Ditto; portion of right facial region, nearly one-half nat. size. 3. Ditto; anterior portion of nasal arcade, right lateral and anterior (3a) aspects, nearly one-half nat. size, na., nasal bones; x, ossification in internasal septum. PLATE VI. Fig. 1. Grypotherium listai; right malar bone, outer aspect, one-half nat. size. 2. Ditto; portion of right mandibular ramus, inner aspect, and dentition of left ramus, oral aspect (2 a), one-half nat. size. U. Ditto ; dentition of another left mandibular ramus, oral aspect, one-half nat. size. 4. Ditto ; auditory ossicles of right side of skull no. 1, twice nat. size. i., incus, inside view; m., malleus, outside view; g., stapes, outside view ; x, facette. 4a. Ditto; incus of left side of skull no. 2, inside view, twice nat. size, showing orbicular bone (o.) attached. I ^ Carnot, " Sur une Application de l'Analyse chimique pour fixer lAge d'Ossements humains pr6historiques," Comptes Eendus, vol. cxv. (1892), pp. 337-339. |
