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Show 192 DR. C. J. EORSYXII MAJOR OJS MIOCENE SQUIRRELS. [Feb. 28, from the Malay region and Borneo, which are both, from the conformation of their molars, not to be distinguished from Sciuropteri, I present an enlarged sketch of the fossil molars, together with the first molar of Sc. tephronulas. The few small differences shown by the comparison of the fossil with the recent species consist in a somewhat larger development of the anterior valley, and some minor details in the rugosities of the enamel. The cusps also, bordering the basin-shaped crown, are somewhat stouter in the fossil. Length of the four grinders:-m3 4, m 2 3*5, m, 3, p, 2-5 millim. This is the first fossil of Sciuropterus recorded. However, 1 am of opinion that Sciurus sansaniensis, Lart., from the Middle Miocene of Sansan, is but a smaller species of Sciuropterus, judging, at least, from an enlarged figure of a molar published by Filholl. Deperet has described and figured as a species of Sciuroides an inferior molar from the Lower Pliocene of Roussillon 2, which so much agrees with the homologous molar in some Sciuropteri (cf. Sc. volans), that I think I a m right in considering the Roussillon tooth a third fossil form of Sciuropterus. But this is not all: under the name of Allomys (Meniscomys), Marsh 3 and Cope * have made known remains of Rodentia from the Miocene of Oregon. Marsh considers them as "probably related to the Flying-Squirrels,'' adding that the teeth are somewhat like those of Ungulates. Cope states5 that "the characters of the dentition of this genus (i. e. Meniscomys) resemble those of the genus Pteromys.^'' The figures given by Cope are insufficient for close comparison, as has already been pointed out by Schlosser : but it would appear from the description that one of the species, M. cavatus, approaches Sciurop>terus and especially Sc, pearsoni. The crowns of the inferior molars are described as basin-shaped; " and although the enamel is wrinkled in a complicated manner, the wrinkles are not elevated as in the other species of the genus. Thus the inferior molars more nearly resemble those of ordinary Sriuridce than do those of the other species of Meniscomys "e. Iu the characters mentioned, these other species would form some approach to Pteromys. W h e n comparing the upper teeth of his Allomys nitons with those of Ungulates, Marsh doubtless refers to the angulate conformation 1 H. Filhol, ' Etudes sur les Mammiferes fossiles de Sansan ' (Paris, 1891), pp. 36, 37, pi. i. fig. 3. 2 Ch. Deperet, " Les animaux pliocenes de Roussillon," Mem. Soc. Geol. de France, Paleontologie, t, i. (Paris, 1890), p. 49, pi. vii. figs. 39, 39a. t.iii. 1892, p. 121, pi. xii. fig. 14. (The text quoted in the last instance refers to an upper molar figured, but there is no fig. 14 on pi. xii.) a O. 0. Marsh, " Notice of some new Vertebrate Fossils" (Ainer. Journ, of Science and Arts, vol. xiv. 1877, p. 253). 1 E. D. Cope, " The Vertebrata of the Tertiary Formations of the West," Book 1.1883 (Rep. Un. States Geol. Survey of the Territ. vol. iii., Washington, 1884). 5 L. c. p. 827. 8 L. c. p. 831. |