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Show 876 MR. OLDPIELD THOMAS ON A N E W [Dec. 17, difficult to believe that the beds are quite so early as Senor Ameghino supposes. Any lingering doubt which may have existed among Naturalists as to the correctness of Ameghino's reference of the Epanorthidee to the Marsupials (and doubt has been thrown on it) is wholly removed by the study of Ceenolestes, which is typically Marsupial in every character. As to the general classification of the Marsupials, a subject already sufficiently difficult in view of the puzzling possession by the Peramelidce of polyprotodonty combined with syndactyly, Ceenolestes apparently only adds to the difficulty, being non-syndactylous like most Polyprotodonts, while it has by dentition nothing to do with them. If anything, however, this fact tends to confirm the tentative opinion expressed in the ' Catalogue of Marsupials,' p. 220, that the primary division of the order should be by dentition, and that syndactyly is a secondary character. Were syndactyly the primary character, the Epanorthidee would be thrown with the Dasyuridce and Didelphyidee, with which they clearly have nothing whatever to do, and separated from what appear to be their nearest allies, tbe Phalanger idee. If this view be correct, the Marsupials as a whole might be divided as follows :- Order MARSUPIALIA. I. Suborder D I P R O T O D O N T A. A. Non-sgndactglous.-American. 1. Epanorthidae. B. Syndadylous.-Australian. 2. Phalangeridae. 3. Phascolomyidae. 4. Macropodidae. II. Suborder POLTPROTODONTA. A. Syndadylous.-Australian. 5. Perarnelidae. B. Xon-syndadylous.-American and Australian. 6. Didelphyidae. 7. Dasyuridae. 8. Notoryctidae. It is, however, possible that, in spite of the resemblance of the teeth of Ceenolestes to those of certain Australian Diprotodonts, the study of further material, including soft parts, skeleton, and milk-teeth, will bring out differences of such importance as to necessitate its subordinal separation from them. In this case the name suggested by Ameghino, Paucituberculata, will be available for the suborder containing Ceenolestes and its fossil allies. Even in that case, however, in view of their many resemblances, it does not seem possible that anything will show that there is no |
