. Annals of natural history. Natural history; Plants. found at Kyson in Suffolk. 193 to the corresponding part of the Opossums as to warrant the expectation that subsequent discoveries may prove the differ- ences above-mentioned to be merely specific. The crown of the spurious molars of the placental Ferae which present the same general form as the fossil,, are thicker from side to side in proportion to their breadth; the spurious molars of the Dasyurus Thylacinus and Phascogale differ in like manner from the fossil. It is in the marsupial genera Didelphys and Perameles that the false molars p
. Annals of natural history. Natural history; Plants. found at Kyson in Suffolk. 193 to the corresponding part of the Opossums as to warrant the expectation that subsequent discoveries may prove the differ- ences above-mentioned to be merely specific. The crown of the spurious molars of the placental Ferae which present the same general form as the fossil,, are thicker from side to side in proportion to their breadth; the spurious molars of the Dasyurus Thylacinus and Phascogale differ in like manner from the fossil. It is in the marsupial genera Didelphys and Perameles that the false molars present the same laterally compressed shape as in the fossil. Now besides the Fig. 2, a. perfect tooth, the fossil includes the empty sockets of two other teeth (fig. 2, b); and the relative position of these sockets places the Perameles out of the pale of comparison. On the hypothesis that the present fossil represents a species of Didelphys, the tooth in Nat. size. situ unquestionabty corresponds with the second or middle false molar, right side, lower jaw. This is proved by the size and position of the anterior alveolus. Had the tooth in situ been the one immediately preceding the true molars, the socket anterior to it should have been at least of equal size, and in juxta-position with the one containing the tooth. The anterior socket, however, is little more than half the size of the one in which the tooth is lodged: it is also separated from that socket by an interspace equal to that ,c. which separates the first from the second false molar in the Didelphys Virginiana. This is well shown in the inside view (fig. 2, c). In the placental mammalia, in which the first small false molar is similarly separated by a dia- inside. Nat. size. sterna from the second, the first false molar has only a single fang. In the present fossil the empty socket of the first false molar proves that that tooth had two fangs as in the marsupial Ferae and Insectivora. There is nothing in the si
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