Proceedings of the Academy of Natural Sciences of Philadelphia

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Excerpt from Proceedings of the Academy of Natural Sciences of Philadelphia: 1889Rodents are notorious for the large size of the premaxillary bones in their skulls, and to this rule the genus now under consideration forms no exception. Here a premaxillary of either side stands between the corresponding nasal and maxillary, preventing those elements of the face from coming in contact at any point. Supe riorly, it sends backwards a lanceolate-shaped apophysis to overlap the frontal of the same Side, and this feature is distinctly shown in Plate I, Figs. 1 and 2.Laterally, it makes up the chief side-wall of the conical fore-part of the Skull of this embryo, and rounds under to form the roof of the anterior part of the mouth, though here a mesially oval foramen largely prevents it from suturally uniting with the fellow of the opposite side down the middle line (plate 1, Fig. Each one anteriorly and beneath shows a diminutive pitlet, in which the inci sor tooth is budding out, the latter not quite filling the hole closely, and withal being yet in an elementary state. Either premaxillary in the oval foramen above referred to, and on the outer aspect of the nasal septum in front, send backwards a teat-like process, into the Spinal Space, and in the skull of the adult Neotoma, these processes seem to have finally each pressed down upon the vomer and fused with its infero-anterior part. A premaxillary articulates with a nasal, a frontal, a lacrymal, the vomer, the ethmoidal mass, and with the fellow of the Opposite side, and at this stage it seems to have progressed in its ossification, about as far as the nasals have, already described above.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.